v3.25.1
INVESTMENTS - STRS JVs individual Investments (Details)
shares in Thousands, $ in Thousands, $ in Thousands
12 Months Ended
Dec. 31, 2024
USD ($)
shares
Dec. 31, 2023
USD ($)
shares
Dec. 31, 2024
CAD ($)
shares
Dec. 31, 2023
CAD ($)
shares
Dec. 31, 2022
USD ($)
Schedule of Investments [Line Items]          
Investment Owned, at Cost $ 695,240 $ 740,021      
Investment Owned, at Fair Value $ 642,213 $ 696,168      
Percent of net assets 224.40% 219.70% 224.40% 219.70%  
Total investments and money market funds amortized cost $ 708,489        
Total investments and money market funds fair value $ 655,462        
Total investments and money market funds percentage 229.00%   229.00%    
STRS JV          
Schedule of Investments [Line Items]          
Investment Owned, at Cost $ 296,752 $ 312,807      
Investments owned non-accrual status 0 0      
Investment Owned, at Fair Value $ 294,957 $ 312,217      
Fair Value As A Percentage of Member's Equity 852.30% 900.60%      
Percent of net assets 852.30% 900.60% 852.30% 900.60%  
Total investments and money market funds amortized cost $ 297,519        
Total investments and money market funds fair value $ 295,724        
Total investments and money market funds percentage 854.50%   854.50%    
Investment, Identifier [Axis]: AB Centers Acquisition Corporation, First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AbCentersAcquisitionCorporationMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Health Care Facilities   Health Care Facilities    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 5.25%   5.25%    
Investment Interest Rate 9.78%   9.78%    
Investment, Acquisition Date Sep. 19, 2024        
Investment Maturity Date Jul. 02, 2031   Jul. 02, 2031    
Investment Owned, Balance, Principal Amount $ 78        
Investment Owned, at Cost 78        
Investment Owned, at Fair Value $ 80        
Fair Value As A Percentage of Member's Equity 0.20%        
Investment, Identifier [Axis]: AB Centers Acquisition Corporation, First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AbCentersAcquisitionCorporationMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Health Care Facilities   Health Care Facilities    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 5.25%   5.25%    
Investment Interest Rate 9.78%   9.78%    
Investment, Acquisition Date Sep. 19, 2024        
Investment Maturity Date Jul. 02, 2031   Jul. 02, 2031    
Investment Owned, at Fair Value $ 5        
Investment, Identifier [Axis]: AB Centers Acquisition Corporation, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AbCentersAcquisitionCorporationMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Health Care Facilities   Health Care Facilities    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 5.25%   5.25%    
Investment Interest Rate 9.79%   9.79%    
Investment, Acquisition Date Sep. 19, 2024        
Investment Maturity Date Jul. 02, 2031   Jul. 02, 2031    
Investment Owned, Balance, Principal Amount $ 7,962        
Investment Owned, at Cost 7,866        
Investment Owned, at Fair Value $ 7,919        
Fair Value As A Percentage of Member's Equity 22.90%        
Investment, Identifier [Axis]: ABB/Con-cise Optical Group LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ABBCon-ciseOpticalGroupLLCMember whfcl:ABBCon-ciseOpticalGroupLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Supplies Health Care Supplies Health Care Supplies Health Care Supplies  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 0.75% 0.75% 0.75% 0.75%  
Spread Above Index 7.50% 7.50% 7.50% 7.50%  
Investment Interest Rate 11.98% 13.01% 11.98% 13.01%  
Investment, Acquisition Date Feb. 23, 2022 Feb. 23, 2022      
Investment Maturity Date Feb. 23, 2028 Feb. 23, 2028 Feb. 23, 2028 Feb. 23, 2028  
Investment Owned, Balance, Principal Amount $ 20,409 $ 20,409      
Investment Owned, at Cost 20,142 20,056      
Investment Owned, at Fair Value $ 19,535 $ 18,983      
Percent of net assets 6.80% 6.00% 6.80% 6.00%  
Investment, Identifier [Axis]: ALM Media, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:ALMMediaLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Data Processing & Outsourced Services   Data Processing & Outsourced Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.00%   6.00%  
Investment Interest Rate   11.50%   11.50%  
Investment, Acquisition Date   Nov. 25, 2019      
Investment Maturity Date   Nov. 25, 2024   Nov. 25, 2024  
Investment Owned, Balance, Principal Amount   $ 12,600      
Investment Owned, at Cost   12,555      
Investment Owned, at Fair Value   $ 12,517      
Percent of net assets   4.00%   4.00%  
Investment, Identifier [Axis]: APG Lions Purchaser, LLC, First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ApgLionsPurchaserLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Distributors   Distributors    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.40%   10.40%    
Investment, Acquisition Date Apr. 26, 2024        
Investment Maturity Date Apr. 16, 2030   Apr. 16, 2030    
Investment Owned, at Fair Value $ 15        
Investment, Identifier [Axis]: APG Lions Purchaser, LLC, First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ApgLionsPurchaserLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Distributors   Distributors    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.40%   10.40%    
Investment, Acquisition Date Apr. 26, 2024        
Investment Maturity Date Apr. 16, 2030   Apr. 16, 2030    
Investment Owned, at Fair Value $ 6        
Investment, Identifier [Axis]: APG Lions Purchaser, LLC, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ApgLionsPurchaserLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Distributors   Distributors    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.40%   10.40%    
Investment, Acquisition Date Apr. 26, 2024        
Investment Maturity Date Apr. 16, 2030   Apr. 16, 2030    
Investment Owned, Balance, Principal Amount $ 4,080        
Investment Owned, at Cost 4,027        
Investment Owned, at Fair Value $ 4,070        
Fair Value As A Percentage of Member's Equity 11.80%        
Investment, Identifier [Axis]: ATSG, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:ATSGIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   IT Consulting And Other Services   IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   12.04%   12.04%  
Investment, Acquisition Date   Mar. 27, 2023      
Investment Maturity Date   Nov. 12, 2026   Nov. 12, 2026  
Investment Owned, Balance, Principal Amount   $ 9,873      
Investment Owned, at Cost   9,678      
Investment Owned, at Fair Value   $ 9,771      
Fair Value As A Percentage of Member's Equity   28.20%      
Investment, Identifier [Axis]: ATSG, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:ATSGIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   IT Consulting And Other Services   IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   12.04%   12.04%  
Investment, Acquisition Date   Nov. 12, 2021      
Investment Maturity Date   Nov. 12, 2026   Nov. 12, 2026  
Investment Owned, Balance, Principal Amount   $ 3,785      
Investment Owned, at Cost   3,741      
Investment Owned, at Fair Value   $ 3,745      
Percent of net assets   1.20%   1.20%  
Investment, Identifier [Axis]: Alvaria Holdco (Cayman) (d/b/a Aspect Software, Inc.) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AlvariaHoldcoMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Application Software   Application Software    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 7.50%   7.50%    
Investment Interest Rate 11.96%   11.96%    
Investment, Acquisition Date Mar. 20, 2024        
Investment Maturity Date May 08, 2028   May 08, 2028    
Investment Owned, Balance, Principal Amount $ 1,782        
Investment Owned, at Cost 1,615        
Investment Owned, at Fair Value $ 1,456        
Investment, Interest Rate, Paid in Kind 6.50%   6.50%    
Investment, Interest Rate, Paid in Cash 5.46%   5.46%    
Percent of net assets 0.50%   0.50%    
Investment, Identifier [Axis]: Alvaria Holdco (Cayman) (d/b/a Aspect Software, Inc.) First Lien Secured Term Loan Four          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AlvariaHoldcoMember        
Investment, Type [Extensible Enumeration] whfcl:SecondLienSecuredTermLoanMember   whfcl:SecondLienSecuredTermLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Application Software   Application Software    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 7.00%   7.00%    
Investment Interest Rate 11.46%   11.46%    
Investment, Acquisition Date Mar. 20, 2024        
Investment Maturity Date May 08, 2028   May 08, 2028    
Investment Owned, Balance, Principal Amount $ 2,400        
Investment Owned, at Cost 2,330        
Investment Owned, at Fair Value $ 74        
Investment, Identifier [Axis]: Alvaria Holdco (Cayman) (d/b/a Aspect Software, Inc.) First Lien Secured Term Loan Three          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AlvariaHoldcoMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Application Software   Application Software    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 7.00%   7.00%    
Investment Interest Rate 11.46%   11.46%    
Investment, Acquisition Date Mar. 20, 2024        
Investment Maturity Date May 08, 2028   May 08, 2028    
Investment Owned, Balance, Principal Amount $ 9,600        
Investment Owned, at Cost 9,318        
Investment Owned, at Fair Value $ 3,990        
Percent of net assets 1.40%   1.40%    
Investment, Identifier [Axis]: Alvaria Holdco (Cayman) (d/b/a Aspect Software, Inc.) First Lien Secured Term Loan Two          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AlvariaHoldcoMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Application Software   Application Software    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 7.50%   7.50%    
Investment Interest Rate 11.96%   11.96%    
Investment, Acquisition Date Mar. 20, 2024        
Investment Maturity Date May 08, 2028   May 08, 2028    
Investment Owned, Balance, Principal Amount $ 1,178        
Investment Owned, at Cost 1,029        
Investment Owned, at Fair Value $ 451        
Investment, Interest Rate, Paid in Kind 5.50%   5.50%    
Investment, Interest Rate, Paid in Cash 6.46%   6.46%    
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: American Crafts Holdings, LLC, Warrants          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AmericanCraftsHoldingsLlcMember whfcl:AmericanCraftsHoldingsLlcMember      
Investment, Type [Extensible Enumeration] Warrant [Member] Warrant [Member] Warrant [Member] Warrant [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Acquisition Date Dec. 22, 2022 Dec. 22, 2022      
Investment Maturity Date Dec. 22, 2032 Dec. 22, 2032 Dec. 22, 2032 Dec. 22, 2032  
Investment, Identifier [Axis]: American Crafts LC Super Priority First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AmericanCraftsLCMember whfcl:AmericanCraftsLCMember      
Investment, Type [Extensible Enumeration] whfcl:SuperPriorityFirstLienSecuredTermLoanMember whfcl:SuperPriorityFirstLienSecuredTermLoanMember whfcl:SuperPriorityFirstLienSecuredTermLoanMember whfcl:SuperPriorityFirstLienSecuredTermLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.50% 8.50% 8.50% 8.50%  
Investment, Acquisition Date Jul. 25, 2023 Jul. 25, 2023      
Investment Maturity Date May 28, 2026 May 28, 2026 May 28, 2026 May 28, 2026  
Investment Owned, Balance, Principal Amount $ 2,191 $ 1,903      
Investment Owned, at Cost $ 2,094 1,903      
Investment Owned, at Fair Value   $ 1,878      
Investment, Interest Rate, Paid in Kind 12.96% 13.96% 12.96% 13.96%  
Percent of net assets   0.60%   0.60%  
Investment, Identifier [Axis]: American Crafts Lc Super Priority First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AmericanCraftsLCMember whfcl:AmericanCraftsLCMember      
Investment, Type [Extensible Enumeration] whfcl:SuperPriorityFirstLienSecuredTermLoanMember whfcl:SuperPriorityFirstLienSecuredTermLoanMember whfcl:SuperPriorityFirstLienSecuredTermLoanMember whfcl:SuperPriorityFirstLienSecuredTermLoanMember  
Investment Owned, at Fair Value   $ 1,878      
Investment, Identifier [Axis]: American Crafts, LC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AmericanCraftsLCMember whfcl:AmericanCraftsLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.50% 8.50% 8.50% 8.50%  
Investment, Acquisition Date Jan. 25, 2022 Jan. 25, 2022      
Investment Maturity Date May 28, 2026 May 28, 2026 May 28, 2026 May 28, 2026  
Investment Owned, Balance, Principal Amount $ 1,823 $ 1,585      
Investment Owned, at Cost $ 1,458 1,458      
Investment Owned, at Fair Value   $ 93      
Investment, Interest Rate, Paid in Kind 12.96% 13.96% 12.96% 13.96%  
Investment, Identifier [Axis]: American Crafts, LC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AmericanCraftsLCMember whfcl:AmericanCraftsLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.50% 8.50% 8.50% 8.50%  
Investment, Acquisition Date May 28, 2021 May 28, 2021      
Investment Maturity Date May 28, 2026 May 28, 2026 May 28, 2026 May 28, 2026  
Investment Owned, Balance, Principal Amount $ 10,859 $ 9,441      
Investment Owned, at Cost $ 8,720 8,720      
Investment Owned, at Fair Value   $ 553      
Investment, Interest Rate, Paid in Kind 12.96% 13.96% 12.96% 13.96%  
Percent of net assets   0.20%   0.20%  
Investment, Identifier [Axis]: American Crafts, LC Priority First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AmericanCraftsLCMember whfcl:AmericanCraftsLCMember      
Investment, Type [Extensible Enumeration] whfcl:PriorityFirstLienSecuredTermLoanMember whfcl:PriorityFirstLienSecuredTermLoanMember whfcl:PriorityFirstLienSecuredTermLoanMember whfcl:PriorityFirstLienSecuredTermLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.50% 8.50% 8.50% 8.50%  
Investment, Acquisition Date Dec. 22, 2022 Dec. 22, 2022      
Investment Maturity Date May 28, 2026 May 28, 2026 May 28, 2026 May 28, 2026  
Investment Owned, Balance, Principal Amount $ 5,876 $ 5,105      
Investment Owned, at Cost $ 5,105 5,105      
Investment Owned, at Fair Value   $ 3,226      
Investment, Interest Rate, Paid in Kind 12.96% 13.96% 12.96% 13.96%  
Percent of net assets   1.00%   1.00%  
Investment, Identifier [Axis]: American Crafts, LC Super Senior Priority First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AmericanCraftsLCMember        
Investment, Type [Extensible Enumeration] whfcl:SuperSeniorPriorityFirstLienSecuredTermLoanMember   whfcl:SuperSeniorPriorityFirstLienSecuredTermLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Leisure Products   Leisure Products    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.50%   8.50%    
Investment, Acquisition Date May 02, 2024        
Investment Maturity Date May 28, 2026   May 28, 2026    
Investment Owned, Balance, Principal Amount $ 2,485        
Investment Owned, at Cost 2,374        
Investment Owned, at Fair Value $ 373        
Percent of net assets 0.10%   0.10%    
Investment, Identifier [Axis]: American Crafts, LC Super Senior Priority First Lien Secured Term Loan One          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AmericanCraftsLCMember        
Investment, Type [Extensible Enumeration] whfcl:SuperSeniorPriorityFirstLienSecuredTermLoanMember   whfcl:SuperSeniorPriorityFirstLienSecuredTermLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Leisure Products   Leisure Products    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.50%   8.50%    
Investment, Acquisition Date Jan. 31, 2024        
Investment Maturity Date May 28, 2026   May 28, 2026    
Investment Owned, Balance, Principal Amount $ 1,287        
Investment Owned, at Cost $ 1,230        
Investment, Interest Rate, Paid in Kind 12.96%   12.96%    
Investment, Identifier [Axis]: American Crafts, LC Super Senior Priority First Lien Secured Term Loan one          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:AmericanCraftsLCMember        
Investment, Type [Extensible Enumeration] whfcl:SuperSeniorPriorityFirstLienSecuredTermLoanMember   whfcl:SuperSeniorPriorityFirstLienSecuredTermLoanMember    
Investment, Identifier [Axis]: Arcole Holding Corporation          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:ArcoleHoldingCorporationMember      
Investment, Identifier [Axis]: Arcole Holding Corporation, Equity          
Schedule of Investments [Line Items]          
Investment, Type [Extensible Enumeration]   Equity Investments   Equity Investments  
Investment Owned, at Fair Value         $ 6,380
Investment, Identifier [Axis]: Arcserve Cayman GP LLC (d/b/a Arcserve (USA), LLC) Common Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ArcserveCaymanGpLlcMember        
Investment, Type [Extensible Enumeration] whfcl:CommonUnitsMember   whfcl:CommonUnitsMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Systems Software   Systems Software    
Investment, Acquisition Date Jan. 03, 2024        
Investment Owned, Balance, Shares | shares 663   663    
Investment, Identifier [Axis]: Arcserve Cayman GP LLC (d/b/a Arcserve (USA), LLC) Common Units One          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ArcserveCaymanGpLlcMember        
Investment, Type [Extensible Enumeration] whfcl:CommonUnitsMember   whfcl:CommonUnitsMember    
Investment, Identifier [Axis]: Arcserve Cayman Opco LP (d/b/a Arcserve (USA), LLC) First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ArcserveCaymanOpcoLpMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Systems Software   Systems Software    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.00%   8.00%    
Investment, Acquisition Date Jan. 03, 2024        
Investment Maturity Date Jan. 04, 2027   Jan. 04, 2027    
Investment Owned, Balance, Principal Amount $ 689        
Investment Owned, at Cost 677        
Investment Owned, at Fair Value $ 1,247        
Investment, Interest Rate, Paid in Kind 12.67%   12.67%    
Percent of net assets 0.40%   0.40%    
Investment, Identifier [Axis]: Arcserve Cayman Opco LP (d/b/a Arcserve (USA), LLC) Unsecured Loan One          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ArcserveCaymanOpcoLpMember        
Investment, Type [Extensible Enumeration] whfcl:UnsecuredLoanMember   whfcl:UnsecuredLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Systems Software   Systems Software    
Investment Interest Rate 9.00%   9.00%    
Investment, Acquisition Date Jan. 03, 2024        
Investment Maturity Date Jul. 02, 2029   Jul. 02, 2029    
Investment Owned, Balance, Principal Amount $ 581        
Investment Owned, at Cost 569        
Investment Owned, at Fair Value $ 581        
Investment, Interest Rate, Paid in Kind 9.00%   9.00%    
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: Arcserve Cayman Opco LP (d/b/a Arcserve (USA), LLC) Unsecured Loan Two          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ArcserveCaymanOpcoLpMember        
Investment, Type [Extensible Enumeration] whfcl:UnsecuredLoanMember   whfcl:UnsecuredLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Systems Software   Systems Software    
Investment Interest Rate 9.00%   9.00%    
Investment, Acquisition Date Jan. 03, 2024        
Investment Maturity Date Jul. 02, 2029   Jul. 02, 2029    
Investment Owned, Balance, Principal Amount $ 594        
Investment Owned, at Cost 583        
Investment Owned, at Fair Value $ 594        
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: Arcserve Cayman Topco LP (d/b/a Arcserve (USA), LLC) Common Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ArcserveCaymanTopcoLpMember        
Investment, Type [Extensible Enumeration] whfcl:CommonUnitsMember   whfcl:CommonUnitsMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Systems Software   Systems Software    
Investment, Acquisition Date Jan. 03, 2024        
Investment Owned, Balance, Shares | shares 663   663    
Investment Owned, at Cost $ 19,568        
Investment Owned, at Fair Value $ 9,131        
Percent of net assets 3.20%   3.20%    
Investment, Identifier [Axis]: Arcserve Cayman Topco LP (d/b/a Arcserve (USA), LLC) Common Units Two          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ArcserveCaymanTopcoLpMember        
Investment, Type [Extensible Enumeration] whfcl:CommonUnitsMember   whfcl:CommonUnitsMember    
Investment Owned, at Fair Value $ 9,131        
Investment, Identifier [Axis]: Arcstor Midco, LLC (d/b/a Arcserve (USA), LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:ArcstorMidcoLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Systems Software   Systems Software  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.75%   7.75%  
Investment, Acquisition Date   Mar. 16, 2021      
Investment Maturity Date   Mar. 16, 2027   Mar. 16, 2027  
Investment Owned, Balance, Principal Amount   $ 21,613      
Investment Owned, at Cost   19,568      
Investment Owned, at Fair Value   $ 10,477      
Investment, Interest Rate, Paid in Kind   13.21%   13.21%  
Percent of net assets   3.30%   3.30%  
Investment, Identifier [Axis]: Arcstor Midco, LLC (d/b/a Arcserve (USA), LLC Priority First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:ArcstorMidcoLLCMember      
Investment, Type [Extensible Enumeration]   whfcl:PriorityFirstLienSecuredDelayedDrawLoanMember   whfcl:PriorityFirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Systems Software   Systems Software  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Spread Above Index   8.00%   8.00%  
Investment, Acquisition Date   Jul. 14, 2023      
Investment Maturity Date   Mar. 16, 2027   Mar. 16, 2027  
Investment Owned, Balance, Principal Amount   $ 1,078      
Investment Owned, at Cost   1,050      
Investment Owned, at Fair Value   $ 1,046      
Investment, Interest Rate, Paid in Kind   13.46%   13.46%  
Percent of net assets   0.30%   0.30%  
Investment, Identifier [Axis]: Arteriocyte Medical Systems, Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ArteriocyteMedicalSystemsInc.Member whfcl:ArteriocyteMedicalSystemsInc.Member      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Supplies Health Care Supplies Health Care Supplies Health Care Supplies  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.00% 6.25% 5.00% 6.25%  
Investment Interest Rate 9.33% 11.60% 9.33% 11.60%  
Investment, Acquisition Date Oct. 25, 2023 Oct. 25, 2023      
Investment Maturity Date Oct. 18, 2028 Oct. 18, 2028 Oct. 18, 2028 Oct. 18, 2028  
Investment Owned, at Fair Value $ 9        
Investment, Identifier [Axis]: Arteriocyte Medical Systems, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ArteriocyteMedicalSystemsInc.Member whfcl:ArteriocyteMedicalSystemsInc.Member      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Supplies Health Care Supplies Health Care Supplies Health Care Supplies  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.00% 6.25% 5.00% 6.25%  
Investment Interest Rate 9.33% 11.60% 9.33% 11.60%  
Investment, Acquisition Date Oct. 25, 2023 Oct. 25, 2023      
Investment Maturity Date Oct. 18, 2028 Oct. 18, 2028 Oct. 18, 2028 Oct. 18, 2028  
Investment Owned, Balance, Principal Amount $ 4,972 $ 5,022      
Investment Owned, at Cost 4,877 4,901      
Investment Owned, at Fair Value $ 5,021 $ 4,901      
Fair Value As A Percentage of Member's Equity 14.50% 14.10%      
Investment, Identifier [Axis]: Atlas Purchaser, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:AtlasPurchaserIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Application Software   Application Software  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   0.75%   0.75%  
Spread Above Index   5.25%   5.25%  
Investment Interest Rate   10.88%   10.88%  
Investment, Acquisition Date   Aug. 29, 2022      
Investment Maturity Date   May 08, 2028   May 08, 2028  
Investment Owned, Balance, Principal Amount   $ 3,066      
Investment Owned, at Cost   2,675      
Investment Owned, at Fair Value   $ 2,269      
Percent of net assets   0.70%   0.70%  
Investment, Identifier [Axis]: Atlas Purchaser, Inc Second Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:AtlasPurchaserIncMember      
Investment, Type [Extensible Enumeration]   whfcl:SecondLienSecuredTermLoanMember   whfcl:SecondLienSecuredTermLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Application Software   Application Software  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   0.75%   0.75%  
Spread Above Index   9.00%   9.00%  
Investment Interest Rate   14.64%   14.64%  
Investment, Acquisition Date   May 03, 2021      
Investment Maturity Date   May 07, 2029   May 07, 2029  
Investment Owned, Balance, Principal Amount   $ 15,000      
Investment Owned, at Cost   14,699      
Investment Owned, at Fair Value   $ 9,744      
Percent of net assets   3.10%   3.10%  
Investment, Identifier [Axis]: Avision Holdings, LLC (d/b/a Avision Sales Group) First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Avision Holdings, LLC [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Advertising   Advertising    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 10.48%   10.48%    
Investment, Acquisition Date May 31, 2024        
Investment Maturity Date Dec. 15, 2026   Dec. 15, 2026    
Investment Owned, Balance, Principal Amount $ 553        
Investment Owned, at Cost 545        
Investment Owned, at Fair Value $ 558        
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: Avision Holdings, LLC (d/b/a Avision Sales Group) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Avision Holdings, LLC [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Advertising   Advertising    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 10.48%   10.48%    
Investment, Acquisition Date May 31, 2024        
Investment Maturity Date Dec. 15, 2026   Dec. 15, 2026    
Investment Owned, Balance, Principal Amount $ 658        
Investment Owned, at Cost 648        
Investment Owned, at Fair Value $ 652        
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: Avision Holdings, LLC Class A LLC Interests          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Avision Holdings, LLC [Member] Avision Holdings, LLC [Member]      
Investment, Type [Extensible Enumeration] whfcl:ClassALLCInterestsMember whfcl:ClassALLCInterestsMember whfcl:ClassALLCInterestsMember whfcl:ClassALLCInterestsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Advertising Advertising Advertising Advertising  
Investment, Acquisition Date Dec. 15, 2021 Dec. 15, 2021      
Investment Owned, Balance, Shares | shares 200 200 200 200  
Investment Owned, at Cost $ 287 $ 287      
Investment Owned, at Fair Value $ 577 $ 411      
Percent of net assets 0.20% 0.10% 0.20% 0.10%  
Investment, Identifier [Axis]: BBQ Buyer, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BBQBuyerLLCMember whfcl:BBQBuyerLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Household Appliances Household Appliances Household Appliances Household Appliances  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.50% 1.50% 1.50% 1.50%  
Spread Above Index 10.50% 9.50% 10.50% 9.50%  
Investment Interest Rate 14.96% 14.96% 14.96% 14.96%  
Investment, Acquisition Date Dec. 02, 2021 Dec. 02, 2021      
Investment Maturity Date Aug. 28, 2025 Aug. 28, 2025 Aug. 28, 2025 Aug. 28, 2025  
Investment Owned, Balance, Principal Amount $ 2,654 $ 2,628      
Investment Owned, at Cost 2,645 2,606      
Investment Owned, at Fair Value $ 2,642 $ 2,613      
Investment, Interest Rate, Paid in Kind 2.00% 1.00% 2.00% 1.00%  
Investment, Interest Rate, Paid in Cash 12.96% 13.96% 12.96% 13.96%  
Percent of net assets 0.90% 0.80% 0.90% 0.80%  
Investment, Identifier [Axis]: BBQ Buyer, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BBQBuyerLLCMember whfcl:BBQBuyerLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Household Appliances Household Appliances Household Appliances Household Appliances  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.50% 1.50% 1.50% 1.50%  
Spread Above Index 10.50% 9.50% 10.50% 9.50%  
Investment Interest Rate 14.96% 14.96% 14.96% 14.96%  
Investment, Acquisition Date Aug. 28, 2020 Aug. 28, 2020      
Investment Maturity Date Aug. 28, 2025 Aug. 28, 2025 Aug. 28, 2025 Aug. 28, 2025  
Investment Owned, Balance, Principal Amount $ 13,013 $ 12,891      
Investment Owned, at Cost 12,972 12,787      
Investment Owned, at Fair Value $ 12,955 $ 12,818      
Investment, Interest Rate, Paid in Kind 2.00% 1.00% 2.00% 1.00%  
Investment, Interest Rate, Paid in Cash 12.96% 13.96% 12.96% 13.96%  
Percent of net assets 4.50% 4.10% 4.50% 4.10%  
Investment, Identifier [Axis]: BBQ Buyer, LLC Shares          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BBQBuyerLLCMember whfcl:BBQBuyerLLCMember      
Investment, Type [Extensible Enumeration] Common Stock [Member] Common Stock [Member] Common Stock [Member] Common Stock [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Household Appliances Household Appliances Household Appliances Household Appliances  
Investment, Acquisition Date Aug. 28, 2020 Aug. 28, 2020      
Investment Owned, Balance, Shares | shares 1,100 1,100 1,100 1,100  
Investment Owned, at Cost $ 1,100 $ 1,100      
Investment Owned, at Fair Value $ 907 $ 1,330      
Percent of net assets 0.30% 0.40% 0.30% 0.40%  
Investment, Identifier [Axis]: BL Products Parent, LP Class A Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BLProductsParentLPMember whfcl:BLProductsParentLPMember      
Investment, Type [Extensible Enumeration] whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Industrial Machinery & Supplies & Components Industrial Machinery & Supplies & Components Industrial Machinery & Supplies & Components Industrial Machinery & Supplies & Components  
Investment, Acquisition Date Feb. 01, 2022 Feb. 01, 2022      
Investment Owned, Balance, Shares | shares 733 733 733 733  
Investment Owned, at Cost $ 788 $ 788      
Investment Owned, at Fair Value $ 1,012 $ 1,053      
Percent of net assets 0.40% 0.30% 0.40% 0.30%  
Investment, Identifier [Axis]: BPII-JL Group Holdings LP Class A Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BPII-JLGroupHoldingsLPMember whfcl:BPII-JLGroupHoldingsLPMember      
Investment, Type [Extensible Enumeration] whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services  
Investment, Acquisition Date Dec. 29, 2021 Dec. 29, 2021      
Investment Owned, Balance, Shares | shares 90 83 90 83  
Investment Owned, at Cost $ 942 $ 825      
Investment Owned, at Fair Value $ 1,400 $ 983      
Percent of net assets 0.50% 0.30% 0.50% 0.30%  
Investment, Identifier [Axis]: BUSA Acquisition Co. (d/b/a BankCard USA Merchant Services Inc.) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Busa Acquisition Co BankCard Usa Merchant Services Inc [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Data Processing & Outsourced Services   Data Processing & Outsourced Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.50%   6.50%    
Investment Interest Rate 10.81%   10.81%    
Investment, Acquisition Date Apr. 04, 2024        
Investment Maturity Date Mar. 30, 2029   Mar. 30, 2029    
Investment Owned, Balance, Principal Amount $ 459        
Investment Owned, at Cost 447        
Investment Owned, at Fair Value $ 461        
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: BUSA Acquisition Co. (d/b/a BankCard USA Merchant Services Inc.) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Busa Acquisition Co BankCard Usa Merchant Services Inc [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Data Processing & Outsourced Services   Data Processing & Outsourced Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.50%   6.50%    
Investment Interest Rate 10.77%   10.77%    
Investment, Acquisition Date Apr. 04, 2024        
Investment Maturity Date Mar. 30, 2029   Mar. 30, 2029    
Investment Owned, Balance, Principal Amount $ 7,779        
Investment Owned, at Cost 7,580        
Investment Owned, at Fair Value $ 7,691        
Percent of net assets 2.70%   2.70%    
Investment, Identifier [Axis]: Banner Acquisition Holdings, LLC (d/b/a Banner Industries, Inc) First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:BannerIndustriesIncMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Construction & Engineering   Construction & Engineering  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.00%   6.00%  
Investment Interest Rate   11.38%   11.38%  
Investment, Acquisition Date   Dec. 01, 2023      
Investment Maturity Date   Jan. 02, 2029   Jan. 02, 2029  
Investment Owned, Balance, Principal Amount   $ 140      
Investment Owned, at Cost   137      
Investment Owned, at Fair Value   $ 137      
Investment, Identifier [Axis]: Banner Acquisition Holdings, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Banner Acquisition Holdings, LLC [Member] Banner Acquisition Holdings, LLC [Member]      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering Construction & Engineering Construction & Engineering Construction & Engineering  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.25% 6.00% 6.25% 6.00%  
Investment Interest Rate 10.59% 11.38% 10.59% 11.38%  
Investment, Acquisition Date Dec. 21, 2023 Dec. 21, 2023      
Investment Maturity Date Jan. 02, 2029 Jan. 02, 2029 Jan. 02, 2029 Jan. 02, 2029  
Investment Owned, Balance, Principal Amount $ 1,502 $ 1,400      
Investment Owned, at Cost 1,472 1,366      
Investment Owned, at Fair Value $ 1,477 $ 1,365      
Fair Value As A Percentage of Member's Equity 4.30% 3.80%      
Investment, Identifier [Axis]: Banner Acquisition Holdings, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Banner Acquisition Holdings, LLC [Member] Banner Acquisition Holdings, LLC [Member]      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering Construction & Engineering Construction & Engineering Construction & Engineering  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.25% 6.00% 6.25% 6.00%  
Investment Interest Rate 10.61% 11.37% 10.61% 11.37%  
Investment, Acquisition Date Dec. 21, 2023 Dec. 21, 2023      
Investment Maturity Date Jan. 02, 2029 Jan. 02, 2029 Jan. 02, 2029 Jan. 02, 2029  
Investment Owned, Balance, Principal Amount $ 420 $ 196      
Investment Owned, at Cost 412 191      
Investment Owned, at Fair Value $ 415 $ 191      
Fair Value As A Percentage of Member's Equity 1.20% 0.60%      
Investment, Identifier [Axis]: Banner Acquisition Holdings, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Banner Acquisition Holdings, LLC [Member] Banner Acquisition Holdings, LLC [Member]      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering Construction & Engineering Construction & Engineering Construction & Engineering  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.25% 6.00% 6.25% 6.00%  
Investment Interest Rate 10.61% 11.38% 10.61% 11.38%  
Investment, Acquisition Date Dec. 21, 2023 Dec. 21, 2023      
Investment Maturity Date Jan. 02, 2029 Jan. 02, 2029 Jan. 02, 2029 Jan. 02, 2029  
Investment Owned, Balance, Principal Amount $ 3,033 $ 3,091      
Investment Owned, at Cost 2,974 3,015      
Investment Owned, at Fair Value $ 2,981 $ 3,015      
Fair Value As A Percentage of Member's Equity 8.60% 8.70%      
Investment, Identifier [Axis]: Barrett Purchaser LLC (d/b/a SIB Development and Consulting, Inc.) First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Barrett Purchaser LLC [Member] Barrett Purchaser LLC [Member]      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Research & Consulting Services Research & Consulting Services Research & Consulting Services Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] whfcl:SecuredOvernightFinancingRateSofrMember Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 0.75% 0.75% 0.75% 0.75%  
Spread Above Index 6.00% 6.00% 6.00% 6.00%  
Investment Interest Rate 10.51% 11.36% 10.51% 11.36%  
Investment, Acquisition Date Jan. 10, 2024 Nov. 21, 2023      
Investment Maturity Date Nov. 21, 2029 Nov. 21, 2029 Nov. 21, 2029 Nov. 21, 2029  
Investment Owned, at Fair Value $ (2)        
Investment, Identifier [Axis]: Barrett Purchaser LLC (d/b/a SIB Development and Consulting, Inc.) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Barrett Purchaser LLC [Member] Barrett Purchaser LLC [Member]      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Research & Consulting Services Research & Consulting Services Research & Consulting Services Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] us-gaap:PrimeRateMember whfcl:SecuredOvernightFinancingRateSofrMember us-gaap:PrimeRateMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 0.75% 0.75% 0.75% 0.75%  
Spread Above Index 5.00% 6.00% 5.00% 6.00%  
Investment Interest Rate 12.50% 11.36% 12.50% 11.36%  
Investment, Acquisition Date Jan. 10, 2024 Nov. 21, 2023      
Investment Maturity Date Nov. 21, 2028 Nov. 21, 2028 Nov. 21, 2028 Nov. 21, 2028  
Investment Owned, Balance, Principal Amount $ 60        
Investment Owned, at Cost 58        
Investment Owned, at Fair Value $ 63        
Fair Value As A Percentage of Member's Equity 0.20%        
Investment, Identifier [Axis]: Barrett Purchaser LLC (d/b/a SIB Development and Consulting, Inc.) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Barrett Purchaser LLC [Member] Barrett Purchaser LLC [Member]      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Research & Consulting Services Research & Consulting Services Research & Consulting Services Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] whfcl:SecuredOvernightFinancingRateSofrMember Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 0.75% 0.75% 0.75% 0.75%  
Spread Above Index 6.00% 6.00% 6.00% 6.00%  
Investment Interest Rate 10.51% 11.36% 10.51% 11.36%  
Investment, Acquisition Date Jan. 10, 2024 Nov. 21, 2023      
Investment Maturity Date Nov. 21, 2029 Nov. 21, 2029 Nov. 21, 2029 Nov. 21, 2029  
Investment Owned, Balance, Principal Amount $ 3,617 $ 3,654      
Investment Owned, at Cost 3,543 3,564      
Investment Owned, at Fair Value $ 3,574 $ 3,564      
Fair Value As A Percentage of Member's Equity 10.30%        
Percent of net assets   1.10%   1.10%  
Investment, Identifier [Axis]: Basel U.S. Acquisition Co., Inc. First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BaselU.s.AcquisitionCo.Inc.Member        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Aerospace & Defense   Aerospace & Defense    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.94%   9.94%    
Investment, Acquisition Date Sep. 13, 2024        
Investment Maturity Date Dec. 05, 2028   Dec. 05, 2028    
Investment Owned, at Fair Value $ 7        
Investment, Identifier [Axis]: Basel U.S. Acquisition Co., Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BaselU.s.AcquisitionCo.Inc.Member        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Aerospace & Defense   Aerospace & Defense    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.94%   9.94%    
Investment, Acquisition Date Sep. 13, 2024        
Investment Maturity Date Dec. 05, 2028   Dec. 05, 2028    
Investment Owned, Balance, Principal Amount $ 3,681        
Investment Owned, at Cost 3,633        
Investment Owned, at Fair Value $ 3,675        
Fair Value As A Percentage of Member's Equity 10.60%        
Investment, Identifier [Axis]: Branford Filtration, LLC (d/b/a Clean Solutions Group) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   Branford Filtration, LLC [Member]      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Environmental & Facilities Services   Environmental & Facilities Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.96%   11.96%  
Investment, Acquisition Date   Nov. 17, 2023      
Investment Maturity Date   Nov. 17, 2028   Nov. 17, 2028  
Investment, Identifier [Axis]: Branford Filtration, LLC (d/b/a Clean Solutions Group) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   Branford Filtration, LLC [Member]      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Environmental & Facilities Services   Environmental & Facilities Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.96%   11.96%  
Investment, Acquisition Date   Nov. 17, 2023      
Investment Maturity Date   Nov. 17, 2028   Nov. 17, 2028  
Investment Owned, Balance, Principal Amount   $ 11,613      
Investment Owned, at Cost   11,358      
Investment Owned, at Fair Value   $ 11,358      
Percent of net assets   3.60%   3.60%  
Investment, Identifier [Axis]: Bridgepoint Healthcare, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BridgepointHealthcareLLCMember whfcl:BridgepointHealthcareLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Facilities Health Care Facilities Health Care Facilities Health Care Facilities  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.00% 8.00% 8.00% 8.00%  
Investment Interest Rate 12.46% 13.46% 12.46% 13.46%  
Investment, Acquisition Date Oct. 05, 2021 Oct. 05, 2021      
Investment Maturity Date Oct. 05, 2026 Oct. 05, 2026 Oct. 05, 2026 Oct. 05, 2026  
Investment Owned, Balance, Principal Amount $ 238        
Investment Owned, at Cost 237        
Investment Owned, at Fair Value $ 231 $ (1)      
Percent of net assets 0.10%   0.10%    
Investment, Identifier [Axis]: Bridgepoint Healthcare, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BridgepointHealthcareLLCMember whfcl:BridgepointHealthcareLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Facilities Health Care Facilities Health Care Facilities Health Care Facilities  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.00% 8.00% 8.00% 8.00%  
Investment Interest Rate 12.46% 13.46% 12.46% 13.46%  
Investment, Acquisition Date Oct. 05, 2021 Oct. 05, 2021      
Investment Maturity Date Oct. 05, 2026 Oct. 05, 2026 Oct. 05, 2026 Oct. 05, 2026  
Investment Owned, Balance, Principal Amount $ 8,517 $ 9,073      
Investment Owned, at Cost 8,457 8,973      
Investment Owned, at Fair Value $ 8,429 $ 8,967      
Percent of net assets 2.90% 2.80% 2.90% 2.80%  
Investment, Identifier [Axis]: Buckeye Acquiror LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BuckeyeAcquirorLlcMember whfcl:BuckeyeAcquirorLlcMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.00% 6.50% 5.00% 6.50%  
Investment Interest Rate 8.45% 11.96% 8.45% 11.96%  
Investment, Acquisition Date Aug. 09, 2023 Aug. 09, 2023      
Investment Maturity Date Aug. 01, 2029 Aug. 01, 2029 Aug. 01, 2029 Aug. 01, 2029  
Investment Owned, Balance, Principal Amount $ 2,168        
Investment Owned, at Cost 2,120        
Investment Owned, at Fair Value $ 2,183 $ (3)      
Fair Value As A Percentage of Member's Equity 6.30%        
Investment, Identifier [Axis]: Buckeye Acquiror LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BuckeyeAcquirorLlcMember whfcl:BuckeyeAcquirorLlcMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 10.96% 11.96% 10.96% 11.96%  
Investment, Acquisition Date Aug. 09, 2023 Aug. 09, 2023      
Investment Maturity Date Aug. 01, 2029 Aug. 01, 2029 Aug. 01, 2029 Aug. 01, 2029  
Investment Owned, Balance, Principal Amount $ 234 $ 180      
Investment Owned, at Cost 230 176      
Investment Owned, at Fair Value $ 248 $ 181      
Fair Value As A Percentage of Member's Equity 0.70% 0.50%      
Investment, Identifier [Axis]: Buckeye Acquiror LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:BuckeyeAcquirorLlcMember whfcl:BuckeyeAcquirorLlcMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.42% 6.50% 6.42% 6.50%  
Investment Interest Rate 10.88% 11.96% 10.88% 11.96%  
Investment, Acquisition Date Aug. 09, 2023 Aug. 09, 2023      
Investment Maturity Date Aug. 01, 2029 Aug. 01, 2029 Aug. 01, 2029 Aug. 01, 2029  
Investment Owned, Balance, Principal Amount $ 6,904 $ 5,985      
Investment Owned, at Cost 6,774 5,845      
Investment Owned, at Fair Value $ 6,952 $ 5,898      
Fair Value As A Percentage of Member's Equity 20.10% 17.00%      
Investment, Identifier [Axis]: Bulk Midco, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:BulkMidcoLLCMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Wireless Telecommunication Services   Wireless Telecommunication Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.50%   7.50%  
Investment Interest Rate   12.96%   12.96%  
Investment, Acquisition Date   Oct. 28, 2022      
Investment Maturity Date   Jun. 10, 2024   Jun. 10, 2024  
Investment Owned, Balance, Principal Amount   $ 2,000      
Investment Owned, at Cost   1,989      
Investment Owned, at Fair Value   $ 1,972      
Investment, Interest Rate, Paid in Kind   1.00%   1.00%  
Investment, Interest Rate, Paid in Cash   11.96%   11.96%  
Percent of net assets   0.60%   0.60%  
Investment, Identifier [Axis]: Bulk Midco, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:BulkMidcoLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Wireless Telecommunication Services   Wireless Telecommunication Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.50%   7.50%  
Investment Interest Rate   12.96%   12.96%  
Investment, Acquisition Date   Oct. 28, 2022      
Investment Maturity Date   Jun. 10, 2024   Jun. 10, 2024  
Investment Owned, Balance, Principal Amount   $ 19,267      
Investment Owned, at Cost   19,237      
Investment Owned, at Fair Value   $ 18,997      
Investment, Interest Rate, Paid in Kind   1.00%   1.00%  
Investment, Interest Rate, Paid in Cash   11.96%   11.96%  
Percent of net assets   6.00%   6.00%  
Investment, Identifier [Axis]: CX Holdco LLC Common Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CXHoldcoLLCMember whfcl:CXHoldcoLLCMember      
Investment, Type [Extensible Enumeration] whfcl:CommonUnitsMember whfcl:CommonUnitsMember whfcl:CommonUnitsMember whfcl:CommonUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Acquisition Date May 04, 2021 May 04, 2021      
Investment Owned, Balance, Shares | shares 1,068 1,068 1,068 1,068  
Investment Owned, at Cost $ 1,116 $ 1,116      
Investment Owned, at Fair Value $ 2,232 $ 1,715      
Percent of net assets 0.80% 0.50% 0.80% 0.50%  
Investment, Identifier [Axis]: Camarillo Fitness Holdings, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CamarilloFitnessHoldingsLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Leisure Facilities [Member]   Leisure Facilities [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.50%   8.50%    
Investment, Acquisition Date Sep. 25, 2024        
Investment Maturity Date Sep. 25, 2029   Sep. 25, 2029    
Investment Owned, Balance, Principal Amount $ 11,738        
Investment Owned, at Cost 10,269        
Investment Owned, at Fair Value $ 10,492        
Investment, Interest Rate, Paid in Kind 12.98%   12.98%    
Percent of net assets 3.70%   3.70%    
Investment, Identifier [Axis]: Camp Facility Services Holdings, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CampFacilityServicesHoldingsLLCMember whfcl:CampFacilityServicesHoldingsLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Real Estate Services Real Estate Services Real Estate Services Real Estate Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 10.96% 11.96% 10.96% 11.96%  
Investment, Acquisition Date Nov. 16, 2021 Nov. 16, 2021      
Investment Maturity Date Nov. 16, 2027 Nov. 16, 2027 Nov. 16, 2027 Nov. 16, 2027  
Investment Owned, Balance, Principal Amount $ 10,424 $ 11,668      
Investment Owned, at Cost 10,325 11,517      
Investment Owned, at Fair Value $ 9,905 $ 11,496      
Percent of net assets 3.50% 3.60% 3.50% 3.60%  
Investment, Identifier [Axis]: Camp Facility Services Parent, LLC Preferred Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CampFacilityServicesParentLLCMember whfcl:CampFacilityServicesParentLLCMember      
Investment, Type [Extensible Enumeration] Preferred Units [Member] Preferred Units [Member] Preferred Units [Member] Preferred Units [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Real Estate Services Real Estate Services Real Estate Services Real Estate Services  
Investment Interest Rate 10.00% 10.00% 10.00% 10.00%  
Investment, Acquisition Date Nov. 16, 2021 Nov. 16, 2021      
Investment Owned, Balance, Shares | shares 15 15 15 15  
Investment Owned, at Cost $ 840 $ 840      
Investment Owned, at Fair Value $ 162 $ 1,023      
Investment, Interest Rate, Paid in Kind 10.00% 10.00% 10.00% 10.00%  
Percent of net assets 0.10% 0.30% 0.10% 0.30%  
Investment, Identifier [Axis]: Cennox Holdings Limited, First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CennoxHoldingsLimitedMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services   IT Consulting And Other Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Sterling Overnight Index Average [Member]   Sterling Overnight Index Average [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 10.40%   10.40%    
Investment, Acquisition Date Sep. 11, 2024        
Investment Maturity Date May 04, 2029   May 04, 2029    
Investment Owned, at Fair Value $ 2        
Investment, Identifier [Axis]: Cennox Holdings Limited, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CennoxHoldingsLimitedMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services   IT Consulting And Other Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Sterling Overnight Index Average [Member]   Sterling Overnight Index Average [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 10.40%   10.40%    
Investment, Acquisition Date Sep. 11, 2024        
Investment Maturity Date May 04, 2029   May 04, 2029    
Investment Owned, Balance, Principal Amount $ 513        
Investment Owned, at Cost 665        
Investment Owned, at Fair Value $ 643        
Fair Value As A Percentage of Member's Equity 1.90%        
Investment, Identifier [Axis]: Cennox Holdings Limited, First lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:CennoxHoldingsLimitedMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   IT Consulting And Other Services   IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Sterling Overnight Index Average [Member]   Sterling Overnight Index Average [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.25%   6.25%  
Investment Interest Rate   11.56%   11.56%  
Investment, Acquisition Date   Jul. 16, 2021      
Investment Maturity Date   May 04, 2026   May 04, 2026  
Investment Owned, Balance, Principal Amount   $ 864      
Investment Owned, at Cost   1,182      
Investment Owned, at Fair Value   $ 1,082      
Investment, Interest Rate, Paid in Kind   0.25%   0.25%  
Investment, Interest Rate, Paid in Cash   11.31%   11.31%  
Fair Value As A Percentage of Member's Equity   3.10%      
Investment, Identifier [Axis]: Cennox Holdings Limited., First lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:CennoxHoldingsLimitedMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   IT Consulting And Other Services   IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Sterling Overnight Index Average [Member]   Sterling Overnight Index Average [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.25%   6.25%  
Investment, Acquisition Date   Jul. 16, 2021      
Investment Maturity Date   May 04, 2026   May 04, 2026  
Investment Owned, Balance, Principal Amount   $ 2,825      
Investment Owned, at Cost   3,863      
Investment Owned, at Fair Value   $ 3,538      
Fair Value As A Percentage of Member's Equity   10.20%      
Investment, Identifier [Axis]: Cennox, Inc, First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CennoxInc.Member        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services   IT Consulting And Other Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 10.25%   10.25%    
Investment, Acquisition Date Sep. 11, 2024        
Investment Maturity Date May 04, 2029   May 04, 2029    
Investment Owned, Balance, Principal Amount $ 29        
Investment Owned, at Cost 29        
Investment Owned, at Fair Value $ 30        
Fair Value As A Percentage of Member's Equity 0.10%        
Investment, Identifier [Axis]: Cennox, Inc, First Lien Secured Term Loan One          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CennoxInc.Member        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services   IT Consulting And Other Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:EuroInterbankOfferedRateMember   whfcl:EuroInterbankOfferedRateMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 9.14%   9.14%    
Investment, Acquisition Date Sep. 11, 2024        
Investment Maturity Date May 04, 2029   May 04, 2029    
Investment Owned, Balance, Principal Amount $ 594        
Investment Owned, at Cost 649        
Investment Owned, at Fair Value $ 611        
Fair Value As A Percentage of Member's Equity 1.80%        
Investment, Identifier [Axis]: Cennox, Inc, First lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:CennoxInc.Member      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   IT Consulting And Other Services   IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:EuroInterbankOfferedRateMember   whfcl:EuroInterbankOfferedRateMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   10.44%   10.44%  
Investment, Acquisition Date   Jun. 28, 2022      
Investment Maturity Date   May 04, 2026   May 04, 2026  
Investment Owned, Balance, Principal Amount   $ 9,422      
Investment Owned, at Cost   9,851      
Investment Owned, at Fair Value   $ 10,257      
Investment, Interest Rate, Paid in Kind   0.25%   0.25%  
Investment, Interest Rate, Paid in Cash   10.19%   10.19%  
Fair Value As A Percentage of Member's Equity   29.60%      
Investment, Identifier [Axis]: Cennox, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CennoxInc.Member        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services   IT Consulting And Other Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 10.34%   10.34%    
Investment, Acquisition Date Sep. 11, 2024        
Investment Maturity Date May 04, 2029   May 04, 2029    
Investment Owned, Balance, Principal Amount $ 3,350        
Investment Owned, at Cost 3,319        
Investment Owned, at Fair Value $ 3,344        
Fair Value As A Percentage of Member's Equity 9.70%        
Investment, Identifier [Axis]: Chase Products Co. (f/k/a Starco) Second Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ChaseProductsCoMember whfcl:ChaseProductsCoMember      
Investment, Type [Extensible Enumeration] whfcl:SecondLienSecuredTermLoanMember whfcl:SecondLienSecuredTermLoanMember whfcl:SecondLienSecuredTermLoanMember whfcl:SecondLienSecuredTermLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Diversified Chemicals [Member] Diversified Chemicals [Member] Diversified Chemicals [Member] Diversified Chemicals [Member]  
Investment Interest Rate 12.00% 12.00% 12.00% 12.00%  
Investment, Acquisition Date Mar. 16, 2023 Mar. 16, 2023      
Investment Maturity Date Mar. 16, 2028 Mar. 16, 2028 Mar. 16, 2028 Mar. 16, 2028  
Investment Owned, Balance, Principal Amount $ 3,342 $ 2,962      
Investment Owned, at Cost 3,342 2,962      
Investment Owned, at Fair Value $ 3,342 $ 2,793      
Investment, Interest Rate, Paid in Kind 12.00% 12.00% 12.00% 12.00%  
Percent of net assets 1.20% 0.90% 1.20% 0.90%  
Investment, Identifier [Axis]: Claridge Products and Equipment, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ClaridgeProductsandEquipmentLLCMember whfcl:ClaridgeProductsandEquipmentLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Construction Materials [Member] Construction Materials [Member] Construction Materials [Member] Construction Materials [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Base Rate [Member] Base Rate [Member] Base Rate [Member] Base Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.31% 7.56% 8.31% 7.56%  
Investment Interest Rate 14.13% 14.41% 14.13% 14.41%  
Investment, Acquisition Date Dec. 30, 2020 Dec. 30, 2020      
Investment Maturity Date Dec. 30, 2025 Dec. 30, 2025 Dec. 30, 2025 Dec. 30, 2025  
Investment Owned, Balance, Principal Amount $ 632 $ 632      
Investment Owned, at Cost 630 628      
Investment Owned, at Fair Value $ 555 $ 496      
Investment, Interest Rate, Paid in Kind 2.25% 1.50% 2.25% 1.50%  
Investment, Interest Rate, Paid in Cash 11.88% 12.91% 11.88% 12.91%  
Percent of net assets 0.20% 0.20% 0.20% 0.20%  
Investment, Identifier [Axis]: Claridge Products and Equipment, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ClaridgeProductsandEquipmentLLCMember whfcl:ClaridgeProductsandEquipmentLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Construction Materials [Member] Construction Materials [Member] Construction Materials [Member] Construction Materials [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.75% 8.00% 8.75% 8.00%  
Investment Interest Rate 13.21% 13.50% 13.21% 13.50%  
Investment, Acquisition Date Dec. 30, 2020 Dec. 30, 2020      
Investment Maturity Date Dec. 30, 2025 Dec. 30, 2025 Dec. 30, 2025 Dec. 30, 2025  
Investment Owned, Balance, Principal Amount $ 5,711 $ 7,452      
Investment Owned, at Cost 5,690 7,395      
Investment Owned, at Fair Value $ 5,085 $ 6,405      
Investment, Interest Rate, Paid in Kind 2.25% 1.50% 2.25% 1.50%  
Investment, Interest Rate, Paid in Cash 10.96% 12.00% 10.96% 12.00%  
Percent of net assets 1.80% 2.00% 1.80% 2.00%  
Investment, Identifier [Axis]: Clark Restaurant Service, LLC, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ClarkRestaurantServiceLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Food Distributors   Food Distributors    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.11%   10.11%    
Investment, Acquisition Date Jun. 14, 2024        
Investment Maturity Date May 10, 2029   May 10, 2029    
Investment Owned, Balance, Principal Amount $ 5,006        
Investment Owned, at Cost 4,919        
Investment Owned, at Fair Value $ 4,993        
Fair Value As A Percentage of Member's Equity 14.40%        
Investment, Identifier [Axis]: CleanChoice Energy, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CleanChoiceEnergyIncMember whfcl:CleanChoiceEnergyIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Electric Utilities [Member] Electric Utilities [Member] Electric Utilities [Member] Electric Utilities [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.59% 7.58% 7.59% 7.58%  
Investment Interest Rate 12.39% 13.14% 12.39% 13.14%  
Investment, Acquisition Date Oct. 12, 2021 Oct. 12, 2021      
Investment Maturity Date Oct. 12, 2026 Oct. 12, 2026 Oct. 12, 2026 Oct. 12, 2026  
Investment Owned, Balance, Principal Amount $ 15,955 $ 15,955      
Investment Owned, at Cost 15,802 15,715      
Investment Owned, at Fair Value $ 16,032 $ 15,954      
Percent of net assets 5.60% 5.00% 5.60% 5.00%  
Investment, Identifier [Axis]: Coastal Television Broadcasting Group LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CoastalTelevisionBroadcastingGroupLLCMember whfcl:CoastalTelevisionBroadcastingGroupLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Broadcasting [Member] Broadcasting [Member] Broadcasting [Member] Broadcasting [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 7.00% 6.50% 7.00%  
Investment Interest Rate 10.96% 12.46% 10.96% 12.46%  
Investment, Acquisition Date Dec. 30, 2021 Dec. 30, 2021      
Investment Maturity Date Dec. 30, 2026 Dec. 30, 2026 Dec. 30, 2026 Dec. 30, 2026  
Investment Owned, at Fair Value $ 1 $ (3)      
Investment, Identifier [Axis]: Coastal Television Broadcasting Group LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:CoastalTelevisionBroadcastingGroupLLCMember whfcl:CoastalTelevisionBroadcastingGroupLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Broadcasting [Member] Broadcasting [Member] Broadcasting [Member] Broadcasting [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 7.00% 6.50% 7.00%  
Investment Interest Rate 10.96% 12.46% 10.96% 12.46%  
Investment, Acquisition Date Dec. 30, 2021 Dec. 30, 2021      
Investment Maturity Date Dec. 30, 2026 Dec. 30, 2026 Dec. 30, 2026 Dec. 30, 2026  
Investment Owned, Balance, Principal Amount $ 7,879 $ 7,418      
Investment Owned, at Cost 7,808 7,329      
Investment Owned, at Fair Value $ 7,832 $ 7,246      
Percent of net assets 2.70% 2.30% 2.70% 2.30%  
Investment, Identifier [Axis]: Drew Foam Companies Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:DrewFoamCompaniesIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Building Products   Building Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.25%   7.25%  
Investment Interest Rate   12.75%   12.75%  
Investment, Acquisition Date   Nov. 09, 2020      
Investment Maturity Date   Nov. 05, 2025   Nov. 05, 2025  
Investment Owned, Balance, Principal Amount   $ 13,644      
Investment Owned, at Cost   13,541      
Investment Owned, at Fair Value   $ 13,313      
Fair Value As A Percentage of Member's Equity   38.40%      
Investment, Identifier [Axis]: Drew Foam Companies Inc, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:DrewFoamCompaniesIncMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Building Products   Building Products    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 10.48%   10.48%    
Investment, Acquisition Date Nov. 09, 2020        
Investment Maturity Date Dec. 07, 2026   Dec. 07, 2026    
Investment Owned, Balance, Principal Amount $ 13,501        
Investment Owned, at Cost 13,445        
Investment Owned, at Fair Value $ 13,437        
Fair Value As A Percentage of Member's Equity 38.80%        
Investment, Identifier [Axis]: E-Phoenix Acquisition Co. Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:E-PhoenixAcquisitionCo.Inc.Member      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   5.50%   5.50%  
Investment Interest Rate   11.00%   11.00%  
Investment, Acquisition Date   Jul. 15, 2021      
Investment Maturity Date   Jun. 23, 2027   Jun. 23, 2027  
Investment Owned, Balance, Principal Amount   $ 8,604      
Investment Owned, at Cost   8,541      
Investment Owned, at Fair Value   $ 8,562      
Fair Value As A Percentage of Member's Equity   24.70%      
Investment, Identifier [Axis]: E-Phoenix Acquisition Co. Inc., First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:E-PhoenixAcquisitionCo.Inc.Member        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Research & Consulting Services   Research & Consulting Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.98%   9.98%    
Investment, Acquisition Date Jul. 15, 2021        
Investment Maturity Date Jun. 23, 2027   Jun. 23, 2027    
Investment Owned, Balance, Principal Amount $ 8,342        
Investment Owned, at Cost 8,299        
Investment Owned, at Fair Value $ 8,342        
Fair Value As A Percentage of Member's Equity 24.10%        
Investment, Identifier [Axis]: Eddy Acquisitions, LLC Preferred Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:EddyAcquisitionsLLCMember whfcl:EddyAcquisitionsLLCMember      
Investment, Type [Extensible Enumeration] Preferred Units [Member] Preferred Units [Member] Preferred Units [Member] Preferred Units [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Education Services [Member] Education Services [Member] Education Services [Member] Education Services [Member]  
Investment Interest Rate 12.00% 12.00% 12.00% 12.00%  
Investment, Acquisition Date Sep. 15, 2021 Sep. 15, 2021      
Investment Owned, Balance, Shares | shares 167 167 167 167  
Investment Owned, at Cost $ 167 $ 167      
Investment Owned, at Fair Value   $ 18      
Investment, Identifier [Axis]: Education Dynamics, LLC Senior Preferred Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:EducationDynamicsLLCMember        
Investment, Type [Extensible Enumeration] whfcl:SeniorPreferredUnitsMember   whfcl:SeniorPreferredUnitsMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Education Services [Member]   Education Services [Member]    
Investment, Acquisition Date Sep. 15, 2021        
Investment Owned, Balance, Shares | shares 167   167    
Investment Owned, at Cost $ 167        
Investment Owned, at Fair Value $ 100        
Investment, Identifier [Axis]: EducationDynamics, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:EducationDynamicsLLCMember whfcl:EducationDynamicsLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Education Services [Member] Education Services [Member] Education Services [Member] Education Services [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 7.00% 6.50% 7.00%  
Investment Interest Rate 10.96% 12.46% 10.96% 12.46%  
Investment, Acquisition Date Sep. 15, 2021 Sep. 15, 2021      
Investment Maturity Date Sep. 15, 2027 Sep. 15, 2026 Sep. 15, 2027 Sep. 15, 2026  
Investment Owned, at Fair Value $ (51) $ (22)      
Investment, Interest Rate, Paid in Kind   0.50%   0.50%  
Investment, Interest Rate, Paid in Cash   11.96%   11.96%  
Investment, Identifier [Axis]: EducationDynamics, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:EducationDynamicsLLCMember whfcl:EducationDynamicsLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Education Services [Member] Education Services [Member] Education Services [Member] Education Services [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 7.00% 6.50% 7.00%  
Investment Interest Rate 10.96% 12.46% 10.96% 12.46%  
Investment, Acquisition Date Sep. 15, 2021 Sep. 15, 2021      
Investment Maturity Date Sep. 15, 2027 Sep. 15, 2026 Sep. 15, 2027 Sep. 15, 2026  
Investment Owned, Balance, Principal Amount $ 13,089 $ 12,784      
Investment Owned, at Cost 12,989 12,647      
Investment Owned, at Fair Value $ 12,449 $ 12,407      
Investment, Interest Rate, Paid in Kind   0.50%   0.50%  
Investment, Interest Rate, Paid in Cash   11.96%   11.96%  
Percent of net assets 4.30% 4.00% 4.30% 4.00%  
Investment, Identifier [Axis]: EducationDynamics, LLC Subordinated Unsecured Term Loa          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:EducationDynamicsLLCMember      
Investment, Type [Extensible Enumeration]   whfcl:SubordinatedUnsecuredTermLoanMember   whfcl:SubordinatedUnsecuredTermLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Education Services [Member]   Education Services [Member]  
Investment Interest Rate   4.00%   4.00%  
Investment, Acquisition Date   Sep. 15, 2021      
Investment Maturity Date   Mar. 15, 2027   Mar. 15, 2027  
Investment Owned, Balance, Principal Amount   $ 167      
Investment Owned, at Cost   167      
Investment Owned, at Fair Value   $ 167      
Percent of net assets   0.10%   0.10%  
Investment, Identifier [Axis]: Empire Office, Inc First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:EmpireOfficeIncMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Office Services And Supplies [Member]   Office Services And Supplies [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.50%   1.50%  
Spread Above Index   6.75%   6.75%  
Investment Interest Rate   12.21%   12.21%  
Investment, Acquisition Date   Aug. 17, 2021      
Investment Maturity Date   Apr. 12, 2024   Apr. 12, 2024  
Investment Owned, Balance, Principal Amount   $ 4,556      
Investment Owned, at Cost   4,545      
Investment Owned, at Fair Value   $ 4,556      
Percent of net assets   1.40%   1.40%  
Investment, Identifier [Axis]: Empire Office, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:EmpireOfficeIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Office Services And Supplies [Member]   Office Services And Supplies [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.50%   1.50%  
Spread Above Index   6.75%   6.75%  
Investment Interest Rate   12.21%   12.21%  
Investment, Acquisition Date   Apr. 12, 2019      
Investment Maturity Date   Apr. 12, 2024   Apr. 12, 2024  
Investment Owned, Balance, Principal Amount   $ 10,947      
Investment Owned, at Cost   10,931      
Investment Owned, at Fair Value   $ 10,947      
Percent of net assets   3.50%   3.50%  
Investment, Identifier [Axis]: Event Services America, Inc. (d/b/a Contemporary Services Corporation) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:EventServicesAmericaIncMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Security & Alarm Services [Member]   Security & Alarm Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.75%   6.75%    
Investment Interest Rate 11.11%   11.11%    
Investment, Acquisition Date Jan. 31, 2024        
Investment Maturity Date Jan. 31, 2029   Jan. 31, 2029    
Investment Owned, Balance, Principal Amount $ 7,000        
Investment Owned, at Cost 6,857        
Investment Owned, at Fair Value $ 7,070        
Percent of net assets 2.50%   2.50%    
Investment, Identifier [Axis]: FGI Acquisition Corp. (d/b/a Flexitallic Group SAS) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:FgiAcquisitionCorpMember whfcl:FgiAcquisitionCorpMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Commodity Chemicals [Member] Commodity Chemicals [Member] Commodity Chemicals [Member] Commodity Chemicals [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 10.98% 12.00% 10.98% 12.00%  
Investment, Acquisition Date Oct. 28, 2019 Oct. 28, 2019      
Investment Maturity Date Oct. 29, 2026 Oct. 29, 2026 Oct. 29, 2026 Oct. 29, 2026  
Investment Owned, Balance, Principal Amount $ 16,026 $ 16,193      
Investment Owned, at Cost 15,765 15,786      
Investment Owned, at Fair Value $ 16,026 $ 16,110      
Percent of net assets 5.60% 5.10% 5.60% 5.10%  
Investment, Identifier [Axis]: FloWorks International LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:FloworksInternationalLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Distributors   Distributors    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.40%   10.40%    
Investment, Acquisition Date Dec. 12, 2024        
Investment Maturity Date Nov. 26, 2031   Nov. 26, 2031    
Investment, Identifier [Axis]: FloWorks International LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:FloworksInternationalLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Distributors   Distributors    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 4.75%   4.75%    
Investment Interest Rate 9.27%   9.27%    
Investment, Acquisition Date Dec. 12, 2024        
Investment Maturity Date Nov. 26, 2031   Nov. 26, 2031    
Investment Owned, Balance, Principal Amount $ 5,333        
Investment Owned, at Cost 5,280        
Investment Owned, at Fair Value $ 5,281        
Fair Value As A Percentage of Member's Equity 15.30%        
Investment, Identifier [Axis]: Foodservices Brand Group, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:FoodservicesBrandGroupLlcMember whfcl:FoodservicesBrandGroupLlcMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Distributors Distributors Distributors Distributors  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.00% 8.00% 8.00% 8.00%  
Investment Interest Rate 12.62% 13.52% 12.62% 13.52%  
Investment, Acquisition Date Nov. 22, 2022 Nov. 22, 2022      
Investment Maturity Date Dec. 09, 2025 Dec. 09, 2025 Dec. 09, 2025 Dec. 09, 2025  
Investment Owned, Balance, Principal Amount $ 357 $ 357      
Investment Owned, at Cost 357 357      
Investment Owned, at Fair Value $ 321 $ 200      
Percent of net assets 0.10% 0.10% 0.10% 0.10%  
Investment, Identifier [Axis]: Foodservices Brand Group, LLC Second Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:FoodservicesBrandGroupLlcMember      
Investment, Type [Extensible Enumeration]   whfcl:SecondLienSecuredTermLoanMember   whfcl:SecondLienSecuredTermLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Distributors   Distributors  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.50%   1.50%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.96%   11.96%  
Investment, Acquisition Date   Nov. 22, 2022      
Investment Maturity Date   Jan. 08, 2026   Jan. 08, 2026  
Investment Owned, Balance, Principal Amount   $ 5,171      
Investment Owned, at Cost   4,915      
Investment Owned, at Fair Value   $ 1,601      
Percent of net assets   0.50%   0.50%  
Investment, Identifier [Axis]: Forward Solutions, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ForwardSolutionsLlcMember whfcl:ForwardSolutionsLlcMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Advertising Advertising Advertising Advertising  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.75% 6.75% 6.75% 6.75%  
Investment Interest Rate 11.23% 12.25% 11.23% 12.25%  
Investment, Acquisition Date Mar. 11, 2022 Mar. 11, 2022      
Investment Maturity Date Dec. 15, 2026 Dec. 15, 2026 Dec. 15, 2026 Dec. 15, 2026  
Investment Owned, Balance, Principal Amount $ 3,023 $ 3,054      
Investment Owned, at Cost 3,000 3,018      
Investment Owned, at Fair Value $ 3,023 $ 3,025      
Fair Value As A Percentage of Member's Equity 8.70% 8.70%      
Investment, Identifier [Axis]: Forward Solutions, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ForwardSolutionsLlcMember whfcl:ForwardSolutionsLlcMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Advertising Advertising Advertising Advertising  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.75% 6.75% 6.75% 6.75%  
Investment Interest Rate 11.23% 12.25% 11.23% 12.25%  
Investment, Acquisition Date Feb. 18, 2022 Feb. 18, 2022      
Investment Maturity Date Dec. 15, 2026 Dec. 15, 2026 Dec. 15, 2026 Dec. 15, 2026  
Investment Owned, at Fair Value $ 5 $ 1      
Investment, Identifier [Axis]: Forward Solutions, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ForwardSolutionsLlcMember whfcl:ForwardSolutionsLlcMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Advertising Advertising Advertising Advertising  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.75% 6.75% 6.75% 6.75%  
Investment Interest Rate 11.23% 12.25% 11.23% 12.25%  
Investment, Acquisition Date Feb. 18, 2022 Feb. 18, 2022      
Investment Maturity Date Dec. 15, 2026 Dec. 15, 2026 Dec. 15, 2026 Dec. 15, 2026  
Investment Owned, Balance, Principal Amount $ 9,007 $ 9,100      
Investment Owned, at Cost 8,937 8,991      
Investment Owned, at Fair Value $ 9,007 $ 9,014      
Fair Value As A Percentage of Member's Equity 26.10% 26.00%      
Investment, Identifier [Axis]: Future Payment Technologies, LP First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:FuturePaymentTechnologiesLPMember whfcl:FuturePaymentTechnologiesLPMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Data Processing & Outsourced Services Data Processing & Outsourced Services Data Processing & Outsourced Services Data Processing & Outsourced Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.25% 8.25% 8.25% 8.25%  
Investment Interest Rate 12.90% 13.69% 12.90% 13.69%  
Investment, Acquisition Date Dec. 23, 2016 Dec. 23, 2016      
Investment Maturity Date Dec. 05, 2025 Dec. 05, 2025 Dec. 05, 2025 Dec. 05, 2025  
Investment Owned, Balance, Principal Amount $ 20,420 $ 21,665      
Investment Owned, at Cost 20,382 21,582      
Investment Owned, at Fair Value $ 20,420 $ 21,480      
Percent of net assets 7.10% 6.80% 7.10% 6.80%  
Investment, Identifier [Axis]: Geo Logic Systems Ltd First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:GeoLogicSystemsLtdMember whfcl:GeoLogicSystemsLtdMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Data Processing & Outsourced Services Data Processing & Outsourced Services Data Processing & Outsourced Services Data Processing & Outsourced Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:CanadianOvernightRepoRateAverageMember whfcl:CanadianDollarOfferedRateMember whfcl:CanadianOvernightRepoRateAverageMember whfcl:CanadianDollarOfferedRateMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.00% 6.50% 6.00% 6.50%  
Investment Interest Rate 9.49% 11.94% 9.49% 11.94%  
Investment, Acquisition Date Jan. 22, 2020 Jan. 22, 2020      
Investment Maturity Date Dec. 21, 2026 Dec. 19, 2024 Dec. 21, 2026 Dec. 19, 2024  
Investment Owned, at Fair Value $ 2 $ 5      
Investment, Identifier [Axis]: Geo Logic Systems Ltd First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:GeoLogicSystemsLtdMember whfcl:GeoLogicSystemsLtdMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Data Processing & Outsourced Services Data Processing & Outsourced Services Data Processing & Outsourced Services Data Processing & Outsourced Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:CanadianOvernightRepoRateAverageMember whfcl:CanadianDollarOfferedRateMember whfcl:CanadianOvernightRepoRateAverageMember whfcl:CanadianDollarOfferedRateMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.00% 6.50% 6.00% 6.50%  
Investment Interest Rate 9.49% 11.94% 9.49% 11.94%  
Investment, Acquisition Date Jan. 22, 2020 Jan. 22, 2020      
Investment Maturity Date Dec. 21, 2026 Dec. 19, 2024 Dec. 21, 2026 Dec. 19, 2024  
Investment Owned, Balance, Principal Amount $ 18,415 $ 19,416      
Investment Owned, at Cost 14,234 14,969      
Investment Owned, at Fair Value $ 12,883 $ 14,654      
Fair Value As A Percentage of Member's Equity 37.20% 42.30%      
Investment, Identifier [Axis]: Gulf Winds International Acquisition, LLC (d/b/a Gulf Winds International, Inc.) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:GulfWindsInternationalAcquisitionLlcMember whfcl:GulfWindsInternationalAcquisitionLlcMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.50% 7.00% 7.50% 7.00%  
Investment Interest Rate 11.95% 12.46% 11.95% 12.46%  
Investment, Acquisition Date Dec. 16, 2022 Dec. 16, 2022      
Investment Maturity Date Dec. 18, 2028 Dec. 18, 2028 Dec. 18, 2028 Dec. 18, 2028  
Investment Owned, Balance, Principal Amount $ 453        
Investment Owned, at Cost 444        
Investment Owned, at Fair Value $ 447 $ 7      
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: Gulf Winds International Acquisition, LLC (d/b/a Gulf Winds International, Inc.) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:GulfWindsInternationalAcquisitionLlcMember whfcl:GulfWindsInternationalAcquisitionLlcMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.60% 7.00% 7.60% 7.00%  
Investment Interest Rate 11.96% 12.46% 11.96% 12.46%  
Investment, Acquisition Date Dec. 16, 2022 Dec. 16, 2022      
Investment Maturity Date Dec. 18, 2028 Dec. 18, 2028 Dec. 18, 2028 Dec. 18, 2028  
Investment Owned, Balance, Principal Amount $ 8,994 $ 4,804      
Investment Owned, at Cost 8,811 4,685      
Investment Owned, at Fair Value $ 8,857 $ 4,738      
Percent of net assets 3.10% 1.50% 3.10% 1.50%  
Investment, Identifier [Axis]: H I G Camarillo, LP, Limited Partners Interests          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:HIGCamarilloLpMember        
Investment, Type [Extensible Enumeration] whfcl:LimitedPartnerInterestsMember   whfcl:LimitedPartnerInterestsMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Leisure Facilities [Member]   Leisure Facilities [Member]    
Investment, Acquisition Date Sep. 25, 2024        
Investment, Identifier [Axis]: HC Salon Holdings, Inc First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:HCSalonHoldingsIncMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   12.11%   12.11%  
Investment, Acquisition Date   Sep. 30, 2021      
Investment Maturity Date   Sep. 30, 2026   Sep. 30, 2026  
Investment Owned, at Fair Value   $ 8      
Investment, Identifier [Axis]: HC Salon Holdings, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:HCSalonHoldingsIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   12.11%   12.11%  
Investment, Acquisition Date   Sep. 30, 2021      
Investment Maturity Date   Sep. 30, 2026   Sep. 30, 2026  
Investment Owned, Balance, Principal Amount   $ 11,404      
Investment Owned, at Cost   11,279      
Investment Owned, at Fair Value   $ 11,404      
Percent of net assets   3.60%   3.60%  
Investment, Identifier [Axis]: HRG Management, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:HRGManagementLLCMember whfcl:HRGManagementLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Real Estate Services Real Estate Services Real Estate Services Real Estate Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Base Rate [Member] Base Rate [Member] Base Rate [Member] Base Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.97% 6.22% 6.97% 6.22%  
Investment Interest Rate 11.29% 12.10% 11.29% 12.10%  
Investment, Acquisition Date Feb. 18, 2022 Feb. 18, 2022      
Investment Maturity Date Oct. 19, 2026 Oct. 19, 2026 Oct. 19, 2026 Oct. 19, 2026  
Investment Owned, Balance, Principal Amount $ 1,395 $ 2,398      
Investment Owned, at Cost 1,384 2,369      
Investment Owned, at Fair Value $ 1,354 $ 2,282      
Fair Value As A Percentage of Member's Equity 3.90% 6.60%      
Investment, Identifier [Axis]: HRG Management, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:HRGManagementLLCMember whfcl:HRGManagementLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Real Estate Services Real Estate Services Real Estate Services Real Estate Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.25% 6.25% 6.25% 6.25%  
Investment Interest Rate 11.02% 11.80% 11.02% 11.80%  
Investment, Acquisition Date Feb. 18, 2022 Feb. 18, 2022      
Investment Maturity Date Oct. 19, 2026 Oct. 19, 2026 Oct. 19, 2026 Oct. 19, 2026  
Investment Owned, Balance, Principal Amount $ 483 $ 596      
Investment Owned, at Cost 480 589      
Investment Owned, at Fair Value $ 455 $ 547      
Fair Value As A Percentage of Member's Equity 1.30% 1.60%      
Investment, Identifier [Axis]: HRG Management, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:HRGManagementLLCMember whfcl:HRGManagementLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Real Estate Services Real Estate Services Real Estate Services Real Estate Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.25% 6.25% 6.25% 6.25%  
Investment Interest Rate 11.02% 11.80% 11.02% 11.80%  
Investment, Acquisition Date Dec. 28, 2021 Dec. 28, 2021      
Investment Maturity Date Oct. 19, 2026 Oct. 19, 2026 Oct. 19, 2026 Oct. 19, 2026  
Investment Owned, Balance, Principal Amount $ 5,563 $ 9,555      
Investment Owned, at Cost 5,523 9,448      
Investment Owned, at Fair Value $ 5,395 $ 9,074      
Fair Value As A Percentage of Member's Equity 15.60% 26.20%      
Investment, Identifier [Axis]: Hollander Intermediate LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:HollanderIntermediateLlcMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Home Furnishings [Member]   Home Furnishings [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   3.00%   3.00%  
Spread Above Index   10.75%   10.75%  
Investment Interest Rate   16.22%   16.22%  
Investment, Acquisition Date   Sep. 19, 2022      
Investment Maturity Date   Sep. 21, 2026   Sep. 21, 2026  
Investment Owned, Balance, Principal Amount   $ 4,689      
Investment Owned, at Cost   4,661      
Investment Owned, at Fair Value   $ 4,179      
Percent of net assets   1.30%   1.30%  
Investment, Identifier [Axis]: Honors Holdings, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   Honors Holdings, LLC [Member]      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Leisure Facilities [Member]   Leisure Facilities [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.37%   6.37%  
Investment Interest Rate   11.90%   11.90%  
Investment, Acquisition Date   Sep. 06, 2019      
Investment Maturity Date   Sep. 06, 2024   Sep. 06, 2024  
Investment Owned, Balance, Principal Amount   $ 4,650      
Investment Owned, at Cost   4,631      
Investment Owned, at Fair Value   $ 4,603      
Percent of net assets   1.50%   1.50%  
Investment, Identifier [Axis]: Honors Holdings, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   Honors Holdings, LLC [Member]      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Leisure Facilities [Member]   Leisure Facilities [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.49%   6.49%  
Investment Interest Rate   12.02%   12.02%  
Investment, Acquisition Date   Sep. 06, 2019      
Investment Maturity Date   Sep. 06, 2024   Sep. 06, 2024  
Investment Owned, Balance, Principal Amount   $ 9,441      
Investment Owned, at Cost   9,375      
Investment Owned, at Fair Value   $ 9,347      
Percent of net assets   3.00%   3.00%  
Investment, Identifier [Axis]: ITS Buyer Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ITSBuyerIncMember whfcl:ITSBuyerIncMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.50% 5.50% 5.50% 5.50%  
Investment Interest Rate 10.35% 11.11% 10.35% 11.11%  
Investment, Acquisition Date Feb. 17, 2022 Feb. 17, 2022      
Investment Maturity Date Jun. 15, 2026 Jun. 15, 2026 Jun. 15, 2026 Jun. 15, 2026  
Investment Owned, at Fair Value $ 4        
Investment, Identifier [Axis]: ITS Buyer Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ITSBuyerIncMember whfcl:ITSBuyerIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.50% 5.50% 5.50% 5.50%  
Investment Interest Rate 10.35% 11.11% 10.35% 11.11%  
Investment, Acquisition Date Feb. 17, 2022 Feb. 17, 2022      
Investment Maturity Date Jun. 15, 2026 Jun. 15, 2026 Jun. 15, 2026 Jun. 15, 2026  
Investment Owned, Balance, Principal Amount $ 3,307 $ 3,541      
Investment Owned, at Cost 3,286 3,503      
Investment Owned, at Fair Value $ 3,307 $ 3,504      
Fair Value As A Percentage of Member's Equity 9.60% 10.10%      
Investment, Identifier [Axis]: ImageOne Industries, LLC Common A Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ImageOneIndustriesLLCMember whfcl:ImageOneIndustriesLLCMember      
Investment, Type [Extensible Enumeration] whfcl:CommonUnitsMember whfcl:CommonAUnitsMember whfcl:CommonUnitsMember whfcl:CommonAUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Advertising Advertising Advertising Advertising  
Investment, Acquisition Date Sep. 20, 2019 Sep. 20, 2019      
Investment Owned, Balance, Shares | shares 235 149 235 149  
Investment Owned, at Cost $ 10 $ 7      
Investment Owned, at Fair Value $ 12 $ 9      
Investment, Identifier [Axis]: Industrial Specialty Services USA LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:IndustrialSpecialtyServicesUSALLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Environmental & Facilities Services   Environmental & Facilities Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.75%   6.75%  
Investment Interest Rate   12.25%   12.25%  
Investment, Acquisition Date   Dec. 31, 2021      
Investment Maturity Date   Dec. 31, 2026   Dec. 31, 2026  
Investment Owned, Balance, Principal Amount   $ 11,767      
Investment Owned, at Cost   11,626      
Investment Owned, at Fair Value   $ 11,537      
Percent of net assets   3.60%   3.60%  
Investment, Identifier [Axis]: JVMC Holdings Corp First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:JVMCHoldingsCorpMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Investment Banking & Brokerage   Investment Banking & Brokerage  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.96%   11.96%  
Investment, Acquisition Date   Feb. 28, 2019      
Investment Maturity Date   Feb. 28, 2024   Feb. 28, 2024  
Investment Owned, Balance, Principal Amount   $ 3,522      
Investment Owned, at Cost   3,521      
Investment Owned, at Fair Value   $ 3,522      
Percent of net assets   1.10%   1.10%  
Investment, Identifier [Axis]: Juniper Landscaping Holdings LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:JuniperLandscapingHoldingsLLCMember whfcl:JuniperLandscapingHoldingsLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.25% 6.25% 6.25% 6.25%  
Investment Interest Rate 10.85% 11.94% 10.85% 11.94%  
Investment, Acquisition Date Mar. 01, 2022 Mar. 01, 2022      
Investment Maturity Date Dec. 29, 2026 Dec. 29, 2026 Dec. 29, 2026 Dec. 29, 2026  
Investment Owned, Balance, Principal Amount $ 2,343 $ 2,366      
Investment Owned, at Cost 2,326 2,341      
Investment Owned, at Fair Value $ 2,343 $ 2,342      
Fair Value As A Percentage of Member's Equity 6.80% 6.80%      
Investment, Identifier [Axis]: Juniper Landscaping Holdings LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:JuniperLandscapingHoldingsLLCMember whfcl:JuniperLandscapingHoldingsLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.25% 6.25% 6.25% 6.25%  
Investment Interest Rate 10.82% 12.11% 10.82% 12.11%  
Investment, Acquisition Date Mar. 01, 2022 Mar. 01, 2022      
Investment Maturity Date Dec. 29, 2026 Dec. 29, 2026 Dec. 29, 2026 Dec. 29, 2026  
Investment Owned, Balance, Principal Amount $ 517 $ 199      
Investment Owned, at Cost 513 197      
Investment Owned, at Fair Value $ 522 $ 193      
Fair Value As A Percentage of Member's Equity 1.50% 0.60%      
Investment, Identifier [Axis]: Juniper Landscaping Holdings LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:JuniperLandscapingHoldingsLLCMember whfcl:JuniperLandscapingHoldingsLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services Environmental & Facilities Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.25% 6.25% 6.25% 6.25%  
Investment Interest Rate 10.84% 11.86% 10.84% 11.86%  
Investment, Acquisition Date Mar. 01, 2022 Mar. 01, 2022      
Investment Maturity Date Dec. 29, 2026 Dec. 29, 2026 Dec. 29, 2026 Dec. 29, 2026  
Investment Owned, Balance, Principal Amount $ 11,078 $ 11,192      
Investment Owned, at Cost 11,000 11,073      
Investment Owned, at Fair Value $ 11,078 $ 11,080      
Fair Value As A Percentage of Member's Equity 32.00% 32.00%      
Investment, Identifier [Axis]: KORE Wireless Group Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:KoreWirelessGroupIncMember whfcl:KoreWirelessGroupIncMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Wireless Telecommunication Services Wireless Telecommunication Services Wireless Telecommunication Services Wireless Telecommunication Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 11.02% 11.88% 11.02% 11.88%  
Investment, Acquisition Date Nov. 27, 2023 Nov. 27, 2023      
Investment Maturity Date Nov. 09, 2028 Nov. 09, 2028 Nov. 09, 2028 Nov. 09, 2028  
Investment Owned, at Fair Value $ 9        
Investment, Identifier [Axis]: KORE Wireless Group Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:KoreWirelessGroupIncMember whfcl:KoreWirelessGroupIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Wireless Telecommunication Services Wireless Telecommunication Services Wireless Telecommunication Services Wireless Telecommunication Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 11.02% 11.88% 11.02% 11.88%  
Investment, Acquisition Date Nov. 27, 2023 Nov. 27, 2023      
Investment Maturity Date Nov. 09, 2028 Nov. 09, 2028 Nov. 09, 2028 Nov. 09, 2028  
Investment Owned, Balance, Principal Amount $ 6,354 $ 6,418      
Investment Owned, at Cost 6,256 6,294      
Investment Owned, at Fair Value $ 6,323 $ 6,295      
Fair Value As A Percentage of Member's Equity 18.30% 18.20%      
Investment, Identifier [Axis]: Kelso Industries LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Kelso Industries L L C [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering   Construction & Engineering    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.09%   10.09%    
Investment, Acquisition Date Dec. 26, 2024        
Investment Maturity Date Dec. 31, 2029   Dec. 31, 2029    
Investment, Identifier [Axis]: Kelso Industries LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Kelso Industries L L C [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering   Construction & Engineering    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.09%   10.09%    
Investment, Acquisition Date Dec. 26, 2024        
Investment Maturity Date Dec. 31, 2029   Dec. 31, 2029    
Investment Owned, Balance, Principal Amount $ 3,611        
Investment Owned, at Cost 3,539        
Investment Owned, at Fair Value $ 3,539        
Percent of net assets 1.20%   1.20%    
Investment, Identifier [Axis]: Keras Holdings, LLC Shares          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:KerasHoldingsLLCMember whfcl:KerasHoldingsLLCMember      
Investment, Type [Extensible Enumeration] Common Stock [Member] Common Stock [Member] Common Stock [Member] Common Stock [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Acquisition Date Dec. 31, 2020 Dec. 31, 2020      
Investment Owned, Balance, Shares | shares 496 496 496 496  
Investment Owned, at Cost $ 496 $ 496      
Investment Owned, at Fair Value $ 779 $ 683      
Percent of net assets 0.30% 0.20% 0.30% 0.20%  
Investment, Identifier [Axis]: LINC Systems, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:LINCSystemsLLCMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.25%   6.25%  
Investment Interest Rate   11.93%   11.93%  
Investment, Acquisition Date   Jun. 22, 2021      
Investment Maturity Date   Feb. 24, 2026   Feb. 24, 2026  
Investment Owned, at Fair Value   $ (1)      
Investment, Identifier [Axis]: LINC Systems, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:LINCSystemsLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.25%   6.25%  
Investment Interest Rate   11.93%   11.93%  
Investment, Acquisition Date   Jun. 22, 2021      
Investment Maturity Date   Feb. 24, 2026   Feb. 24, 2026  
Investment Owned, Balance, Principal Amount   $ 8,534      
Investment Owned, at Cost   8,454      
Investment Owned, at Fair Value   $ 8,443      
Fair Value As A Percentage of Member's Equity   24.40%      
Investment, Identifier [Axis]: LINC Systems, LLC, First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LINCSystemsLLCMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.50%   8.50%    
Investment Interest Rate 12.99%   12.99%    
Investment, Acquisition Date Jun. 22, 2021        
Investment Maturity Date Feb. 24, 2026   Feb. 24, 2026    
Investment Owned, at Fair Value $ 3        
Investment, Identifier [Axis]: LINC Systems, LLC, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LINCSystemsLLCMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.50%   8.50%    
Investment Interest Rate 12.99%   12.99%    
Investment, Acquisition Date Jun. 22, 2021        
Investment Maturity Date Feb. 24, 2026   Feb. 24, 2026    
Investment Owned, Balance, Principal Amount $ 8,155        
Investment Owned, at Cost 8,114        
Investment Owned, at Fair Value $ 8,155        
Fair Value As A Percentage of Member's Equity 23.70%        
Investment, Identifier [Axis]: LMG Holdings, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:LMGHoldingsIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Electronic Equipment & Instruments   Electronic Equipment & Instruments  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   12.00%   12.00%  
Investment, Acquisition Date   Jun. 28, 2021      
Investment Maturity Date   Apr. 30, 2026   Apr. 30, 2026  
Investment Owned, Balance, Principal Amount   $ 13,330      
Investment Owned, at Cost   13,203      
Investment Owned, at Fair Value   $ 13,265      
Fair Value As A Percentage of Member's Equity   38.30%      
Investment, Identifier [Axis]: LMG Holdings, Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:LMGHoldingsIncMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Electronic Equipment & Instruments   Electronic Equipment & Instruments  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   12.00%   12.00%  
Investment, Acquisition Date   Jun. 28, 2021      
Investment Maturity Date   Apr. 30, 2026   Apr. 30, 2026  
Investment Owned, at Fair Value   $ 4      
Investment, Identifier [Axis]: LSCS Holdings, Inc Second Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LSCSHoldingsIncMember whfcl:LSCSHoldingsIncMember      
Investment, Type [Extensible Enumeration] whfcl:SecondLienSecuredTermLoanMember whfcl:SecondLienSecuredTermLoanMember whfcl:SecondLienSecuredTermLoanMember whfcl:SecondLienSecuredTermLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Life Sciences Tools And Services [Member] Life Sciences Tools And Services [Member] Life Sciences Tools And Services [Member] Life Sciences Tools And Services [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 0.50% 0.50% 0.50% 0.50%  
Spread Above Index 8.00% 8.00% 8.00% 8.00%  
Investment Interest Rate 12.47% 13.47% 12.47% 13.47%  
Investment, Acquisition Date Nov. 23, 2021 Nov. 23, 2021      
Investment Maturity Date Dec. 16, 2029 Dec. 16, 2029 Dec. 16, 2029 Dec. 16, 2029  
Investment Owned, Balance, Principal Amount $ 5,000 $ 5,000      
Investment Owned, at Cost 4,953 4,944      
Investment Owned, at Fair Value $ 5,000 $ 4,901      
Percent of net assets 1.70% 1.50% 1.70% 1.50%  
Investment, Identifier [Axis]: Lab Logistics, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LabLogisticsLLCMember whfcl:LabLogisticsLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Services Health Care Services Health Care Services Health Care Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.25% 7.25% 7.25% 7.25%  
Investment Interest Rate 11.71% 12.71% 11.71% 12.71%  
Investment, Acquisition Date Oct. 16, 2019 Oct. 16, 2019      
Investment Maturity Date Dec. 31, 2025 Sep. 25, 2024 Dec. 31, 2025 Sep. 25, 2024  
Investment Owned, Balance, Principal Amount $ 5,020 $ 5,090      
Investment Owned, at Cost 5,020 5,089      
Investment Owned, at Fair Value $ 5,020 $ 5,090      
Percent of net assets 1.80% 1.60% 1.80% 1.60%  
Investment, Identifier [Axis]: Lab Logistics, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LabLogisticsLLCMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Health Care Services   Health Care Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 7.25%   7.25%    
Investment Interest Rate 11.71%   11.71%    
Investment, Acquisition Date Sep. 17, 2024        
Investment Maturity Date Dec. 31, 2025   Dec. 31, 2025    
Investment Owned, Balance, Principal Amount $ 437        
Investment Owned, at Cost 437        
Investment Owned, at Fair Value $ 437        
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: Lab Logistics, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LabLogisticsLLCMember whfcl:LabLogisticsLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Services Health Care Services Health Care Services Health Care Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.25% 7.25% 7.25% 7.25%  
Investment Interest Rate 11.71% 12.71% 11.71% 12.71%  
Investment, Acquisition Date Oct. 16, 2019 Oct. 16, 2019      
Investment Maturity Date Dec. 31, 2025 Sep. 25, 2024 Dec. 31, 2025 Sep. 25, 2024  
Investment Owned, Balance, Principal Amount $ 5,383 $ 5,449      
Investment Owned, at Cost 5,381 5,442      
Investment Owned, at Fair Value $ 5,383 $ 5,449      
Percent of net assets 1.90% 1.70% 1.90% 1.70%  
Investment, Identifier [Axis]: Leviathan Intermediate Holdco, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LeviathanIntermediateHoldcoLlcMember whfcl:LeviathanIntermediateHoldcoLlcMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.50% 1.50% 1.50% 1.50%  
Spread Above Index 7.50% 7.50% 7.50% 7.50%  
Investment Interest Rate 11.98% 13.00% 11.98% 13.00%  
Investment, Acquisition Date Dec. 27, 2022 Dec. 27, 2022      
Investment Maturity Date Dec. 27, 2027 Dec. 27, 2027 Dec. 27, 2027 Dec. 27, 2027  
Investment Owned, at Fair Value $ 10 $ 14      
Investment, Identifier [Axis]: Leviathan Intermediate Holdco, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LeviathanIntermediateHoldcoLlcMember whfcl:LeviathanIntermediateHoldcoLlcMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.50% 1.50% 1.50% 1.50%  
Spread Above Index 7.50% 7.50% 7.50% 7.50%  
Investment Interest Rate 11.98% 13.00% 11.98% 13.00%  
Investment, Acquisition Date Dec. 27, 2022 Dec. 27, 2022      
Investment Maturity Date Dec. 27, 2027 Dec. 27, 2027 Dec. 27, 2027 Dec. 27, 2027  
Investment Owned, Balance, Principal Amount $ 13,211 $ 10,346      
Investment Owned, at Cost 12,981 10,098      
Investment Owned, at Fair Value $ 13,312 $ 10,346      
Percent of net assets 4.60% 3.30% 4.60% 3.30%  
Investment, Identifier [Axis]: Lift Brands, Inc First Lien Secured Term Loan A          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LiftBrandsIncMember whfcl:LiftBrandsIncMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredTermLoanAMember whfcl:FirstLienSecuredTermLoanAMember whfcl:FirstLienSecuredTermLoanAMember whfcl:FirstLienSecuredTermLoanAMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.50% 7.50% 7.50% 7.50%  
Investment Interest Rate 11.96% 12.96% 11.96% 12.96%  
Investment, Acquisition Date Jun. 29, 2020 Jun. 29, 2020      
Investment Maturity Date Jun. 29, 2025 Jun. 29, 2025 Jun. 29, 2025 Jun. 29, 2025  
Investment Owned, Balance, Principal Amount $ 5,461 $ 5,518      
Investment Owned, at Cost 5,453 5,492      
Investment Owned, at Fair Value $ 5,461 $ 5,457      
Percent of net assets 1.90% 1.70% 1.90% 1.70%  
Investment, Identifier [Axis]: Lift Brands, Inc First Lien Secured Term Loan B          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LiftBrandsIncMember whfcl:LiftBrandsIncMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredTermLoanBMember whfcl:FirstLienSecuredTermLoanBMember whfcl:FirstLienSecuredTermLoanBMember whfcl:FirstLienSecuredTermLoanBMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member]  
Investment Interest Rate 9.50% 9.50% 9.50% 9.50%  
Investment, Acquisition Date Jun. 29, 2020 Jun. 29, 2020      
Investment Maturity Date Jun. 29, 2025 Jun. 29, 2025 Jun. 29, 2025 Jun. 29, 2025  
Investment Owned, Balance, Principal Amount $ 1,594 $ 1,450      
Investment Owned, at Cost 1,592 1,441      
Investment Owned, at Fair Value $ 1,594 $ 1,406      
Investment, Interest Rate, Paid in Kind   9.50%   9.50%  
Percent of net assets 0.60% 0.40% 0.60% 0.40%  
Investment, Identifier [Axis]: LogicMonitor, Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] LogicMonitor, Inc. [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Systems Software   Systems Software    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.99%   9.99%    
Investment, Acquisition Date Nov. 19, 2024        
Investment Maturity Date Nov. 19, 2031   Nov. 19, 2031    
Investment, Identifier [Axis]: LogicMonitor, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] LogicMonitor, Inc. [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Systems Software   Systems Software    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 0.75%   0.75%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.99%   9.99%    
Investment, Acquisition Date Nov. 19, 2024        
Investment Maturity Date Nov. 19, 2031   Nov. 19, 2031    
Investment Owned, Balance, Principal Amount $ 6,220        
Investment Owned, at Cost 6,144        
Investment Owned, at Fair Value $ 6,144        
Percent of net assets 2.10%   2.10%    
Investment, Identifier [Axis]: Luxury Brand Holdings, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:LuxuryBrandHoldingsIncMember whfcl:LuxuryBrandHoldingsIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Broadline Retail Broadline Retail Broadline Retail Broadline Retail  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.75% 6.50% 5.75% 6.50%  
Investment Interest Rate 10.11% 11.96% 10.11% 11.96%  
Investment, Acquisition Date Dec. 04, 2020 Dec. 04, 2020      
Investment Maturity Date Jun. 04, 2026 Jun. 04, 2026 Jun. 04, 2026 Jun. 04, 2026  
Investment Owned, Balance, Principal Amount $ 4,580 $ 5,280      
Investment Owned, at Cost 4,556 5,233      
Investment Owned, at Fair Value $ 4,580 $ 5,280      
Percent of net assets 1.60% 1.70% 1.60% 1.70%  
Investment, Identifier [Axis]: M2S Group Intermediate Holdings, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:M2sGroupIntermediateHoldingsIncMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Paper Products   Paper Products    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Base Rate [Member]   Base Rate [Member]    
Investment, Interest Rate, Floor 0.50%   0.50%    
Spread Above Index 4.73%   4.73%    
Investment Interest Rate 9.10%   9.10%    
Investment, Acquisition Date Aug. 22, 2024        
Investment Maturity Date Aug. 25, 2031   Aug. 25, 2031    
Investment Owned, Balance, Principal Amount $ 9,770        
Investment Owned, at Cost 9,119        
Investment Owned, at Fair Value $ 9,453        
Percent of net assets 3.30%   3.30%    
Investment, Identifier [Axis]: MBS Highway, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MbsHighwayLlcMember whfcl:MbsHighwayLlcMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Application Software Application Software Application Software Application Software  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.50% 7.50% 8.50% 7.50%  
Investment Interest Rate 13.20% 13.18% 13.20% 13.18%  
Investment, Acquisition Date Oct. 13, 2022 Oct. 13, 2022      
Investment Maturity Date Oct. 13, 2027 Oct. 13, 2027 Oct. 13, 2027 Oct. 13, 2027  
Investment Owned, Balance, Principal Amount $ 9,286 $ 9,381      
Investment Owned, at Cost 9,157 9,204      
Investment Owned, at Fair Value $ 9,212 $ 9,089      
Investment, Interest Rate, Paid in Kind 0.50%   0.50%    
Investment, Interest Rate, Paid in Cash 12.70%   12.70%    
Percent of net assets 3.20% 2.90% 3.20% 2.90%  
Investment, Identifier [Axis]: MGT Merger Target, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MgtMergerTargetLlcMember whfcl:MgtMergerTargetLlcMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.97% 6.50% 5.97% 6.50%  
Investment Interest Rate 10.51% 11.98% 10.51% 11.98%  
Investment, Acquisition Date May 10, 2023 May 10, 2023      
Investment Maturity Date Apr. 10, 2029 Apr. 10, 2029 Apr. 10, 2029 Apr. 10, 2029  
Investment Owned, Balance, Principal Amount $ 821 $ 392      
Investment Owned, at Cost 804 378      
Investment Owned, at Fair Value $ 817 $ 389      
Fair Value As A Percentage of Member's Equity 2.40% 1.10%      
Investment, Identifier [Axis]: MGT Merger Target, LLC First lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MgtMergerTargetLlcMember whfcl:MgtMergerTargetLlcMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] us-gaap:PrimeRateMember Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] us-gaap:PrimeRateMember Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.50% 6.50% 5.50% 6.50%  
Investment Interest Rate 13.00% 11.98% 13.00% 11.98%  
Investment, Acquisition Date May 10, 2023 May 10, 2023      
Investment Maturity Date Apr. 10, 2028 Apr. 10, 2028 Apr. 10, 2028 Apr. 10, 2028  
Investment Owned, Balance, Principal Amount $ 241        
Investment Owned, at Cost 236        
Investment Owned, at Fair Value $ 249 $ 11      
Fair Value As A Percentage of Member's Equity 0.70%        
Investment, Identifier [Axis]: MGT Merger Target, LLC First lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MgtMergerTargetLlcMember whfcl:MgtMergerTargetLlcMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.39% 6.50% 6.39% 6.50%  
Investment Interest Rate 10.85% 11.98% 10.85% 11.98%  
Investment, Acquisition Date May 10, 2023 May 10, 2023      
Investment Maturity Date Apr. 10, 2029 Apr. 10, 2029 Apr. 10, 2029 Apr. 10, 2029  
Investment Owned, Balance, Principal Amount $ 7,187 $ 6,247      
Investment Owned, at Cost 7,040 6,084      
Investment Owned, at Fair Value $ 7,176 $ 6,194      
Fair Value As A Percentage of Member's Equity 20.70% 17.90%      
Investment, Identifier [Axis]: MSI Information Services, Inc First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MSIInformationServicesIncMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Education Services [Member]   Education Services [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Base Rate [Member]   Base Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.84%   6.84%  
Investment Interest Rate   15.06%   15.06%  
Investment, Acquisition Date   Apr. 25, 2022      
Investment Maturity Date   Apr. 24, 2026   Apr. 24, 2026  
Investment Owned, Balance, Principal Amount   $ 825      
Investment Owned, at Cost   815      
Investment Owned, at Fair Value   $ 776      
Percent of net assets   0.20%   0.20%  
Investment, Identifier [Axis]: MSI Information Services, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MSIInformationServicesIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Education Services [Member]   Education Services [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.75%   7.75%  
Investment Interest Rate   13.29%   13.29%  
Investment, Acquisition Date   Apr. 25, 2022      
Investment Maturity Date   Apr. 24, 2026   Apr. 24, 2026  
Investment Owned, Balance, Principal Amount   $ 7,333      
Investment Owned, at Cost   7,248      
Investment Owned, at Fair Value   $ 6,972      
Percent of net assets   2.20%   2.20%  
Investment, Identifier [Axis]: MSI Information Services, Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MSIInformationServicesIncMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Education Services [Member]   Education Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Base Rate [Member]   Base Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.82%   8.82%    
Investment Interest Rate 15.24%   15.24%    
Investment, Acquisition Date Apr. 25, 2022        
Investment Maturity Date Apr. 24, 2026   Apr. 24, 2026    
Investment Owned, Balance, Principal Amount $ 1,050        
Investment Owned, at Cost 1,043        
Investment Owned, at Fair Value $ 945        
Percent of net assets 0.30%   0.30%    
Investment, Identifier [Axis]: MSI Information Services, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MSIInformationServicesIncMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Education Services [Member]   Education Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 9.75%   9.75%    
Investment Interest Rate 14.23%   14.23%    
Investment, Acquisition Date Apr. 25, 2022        
Investment Maturity Date Apr. 24, 2026   Apr. 24, 2026    
Investment Owned, Balance, Principal Amount $ 8,746        
Investment Owned, at Cost 8,552        
Investment Owned, at Fair Value $ 7,871        
Percent of net assets 2.80%   2.80%    
Investment, Identifier [Axis]: Mamp;M OpCo. LLC (d/b/a Escalent, Inc.) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] M&M OpCo. LLC (d/b/a Escalent, Inc.) M&M OpCo. LLC (d/b/a Escalent, Inc.)      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Research & Consulting Services Research & Consulting Services Research & Consulting Services Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.00% 8.00% 8.00% 8.00%  
Investment Interest Rate 12.43% 13.45% 12.43% 13.45%  
Investment, Acquisition Date Apr. 07, 2023 Apr. 07, 2023      
Investment Maturity Date Apr. 09, 2029 Apr. 09, 2029 Apr. 09, 2029 Apr. 09, 2029  
Investment Owned, at Fair Value $ 5 $ (1)      
Investment, Identifier [Axis]: Mamp;M OpCo. LLC (d/b/a Escalent, Inc.) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] M&M OpCo. LLC (d/b/a Escalent, Inc.) M&M OpCo. LLC (d/b/a Escalent, Inc.)      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Research & Consulting Services Research & Consulting Services Research & Consulting Services Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.00% 8.00% 8.00% 8.00%  
Investment Interest Rate 12.43% 13.45% 12.43% 13.45%  
Investment, Acquisition Date Apr. 07, 2023 Apr. 07, 2023      
Investment Maturity Date Apr. 09, 2029 Apr. 09, 2029 Apr. 09, 2029 Apr. 09, 2029  
Investment Owned, Balance, Principal Amount $ 4,927 $ 4,726      
Investment Owned, at Cost 4,823 4,602      
Investment Owned, at Fair Value $ 4,922 $ 4,580      
Percent of net assets 1.70% 1.40% 1.70% 1.40%  
Investment, Identifier [Axis]: Manchester Acquisition Sub LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:ManchesterAcquisitionSubLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Diversified Chemicals [Member]   Diversified Chemicals [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   0.75%   0.75%  
Spread Above Index   5.75%   5.75%  
Investment Interest Rate   11.28%   11.28%  
Investment, Acquisition Date   Nov. 16, 2021      
Investment Maturity Date   Dec. 01, 2026   Dec. 01, 2026  
Investment Owned, Balance, Principal Amount   $ 7,840      
Investment Owned, at Cost   7,587      
Investment Owned, at Fair Value   $ 7,215      
Percent of net assets   2.30%   2.30%  
Investment, Identifier [Axis]: Marlin DTC-LS Midco 2, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MarlinDTC-LSMidco2LLCMember whfcl:MarlinDTC-LSMidco2LLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Broadline Retail Broadline Retail Broadline Retail Broadline Retail  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 11.03% 11.99% 11.03% 11.99%  
Investment, Acquisition Date Jul. 19, 2019 Jul. 19, 2019      
Investment Maturity Date Jul. 01, 2025 Jul. 01, 2025 Jul. 01, 2025 Jul. 01, 2025  
Investment Owned, at Fair Value $ (38) $ (3)      
Fair Value As A Percentage of Member's Equity (0.10%)        
Investment, Identifier [Axis]: Marlin DTC-LS Midco 2, LLC First Lien Secured Term          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MarlinDTC-LSMidco2LLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Broadline Retail   Broadline Retail  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.99%   11.99%  
Investment, Acquisition Date   Jul. 19, 2019      
Investment Maturity Date   Jul. 01, 2025   Jul. 01, 2025  
Investment Owned, Balance, Principal Amount   $ 18,908      
Investment Owned, at Cost   18,798      
Investment Owned, at Fair Value   $ 18,762      
Fair Value As A Percentage of Member's Equity   54.10%      
Investment, Identifier [Axis]: Marlin DTC-LS Midco 2, LLC, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MarlinDTC-LSMidco2LLCMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Broadline Retail   Broadline Retail    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.50%   6.50%    
Investment Interest Rate 11.03%   11.03%    
Investment, Acquisition Date Jul. 19, 2019        
Investment Maturity Date Jul. 01, 2025   Jul. 01, 2025    
Investment Owned, Balance, Principal Amount $ 18,613        
Investment Owned, at Cost 18,577        
Investment Owned, at Fair Value $ 17,865        
Fair Value As A Percentage of Member's Equity 51.60%        
Investment, Identifier [Axis]: Max Solutions Inc. Common Stock          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MaxSolutionsIncMember whfcl:MaxSolutionsIncMember      
Investment, Type [Extensible Enumeration] Common Stock [Member] Common Stock [Member] Common Stock [Member] Common Stock [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Paper & Plastic Packaging Products & Materials Paper & Plastic Packaging Products & Materials Paper & Plastic Packaging Products & Materials Paper & Plastic Packaging Products & Materials  
Investment, Acquisition Date Sep. 29, 2022 Sep. 29, 2022      
Investment Owned, Balance, Shares | shares 4 4 4 4  
Investment Owned, at Cost $ 400 $ 400      
Investment Owned, at Fair Value   $ 179      
Percent of net assets   0.10%   0.10%  
Investment, Identifier [Axis]: Max Solutions, Inc. First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MaxSolutionsIncMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.66%   7.66%  
Investment Interest Rate   13.15%   13.15%  
Investment, Acquisition Date   Oct. 07, 2022      
Investment Maturity Date   Sep. 29, 2028   Sep. 29, 2028  
Investment Owned, at Fair Value   $ (17)      
Investment, Identifier [Axis]: Max Solutions, Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MaxSolutionsIncMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:CanadianDollarOfferedRateMember   whfcl:CanadianDollarOfferedRateMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.66%   7.66%  
Investment Interest Rate   13.15%   13.15%  
Investment, Acquisition Date   Oct. 07, 2022      
Investment Maturity Date   Sep. 29, 2028   Sep. 29, 2028  
Investment, Identifier [Axis]: Max Solutions, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MaxSolutionsIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.66%   7.66%  
Investment Interest Rate   13.15%   13.15%  
Investment, Acquisition Date   Oct. 07, 2022      
Investment Maturity Date   Sep. 29, 2028   Sep. 29, 2028  
Investment Owned, Balance, Principal Amount   $ 6,589      
Investment Owned, at Cost   6,485      
Investment Owned, at Fair Value   $ 6,488      
Fair Value As A Percentage of Member's Equity   18.70%      
Investment, Identifier [Axis]: Max Solutions, Inc., First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MaxSolutionsIncMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.10%   8.10%    
Investment Interest Rate 12.56%   12.56%    
Investment, Acquisition Date Oct. 07, 2022        
Investment Maturity Date Sep. 29, 2028   Sep. 29, 2028    
Investment Owned, Balance, Principal Amount $ 414        
Investment Owned, at Cost 411        
Investment Owned, at Fair Value $ 402        
Fair Value As A Percentage of Member's Equity 1.20%        
Investment, Identifier [Axis]: Max Solutions, Inc., First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MaxSolutionsIncMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:CanadianOvernightRepoRateAverageMember   whfcl:CanadianOvernightRepoRateAverageMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.10%   8.10%    
Investment Interest Rate 12.56%   12.56%    
Investment, Acquisition Date Oct. 07, 2022        
Investment Maturity Date Sep. 29, 2028   Sep. 29, 2028    
Investment Owned, at Fair Value $ (3)        
Investment, Identifier [Axis]: Max Solutions, Inc., First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MaxSolutionsIncMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Paper & Plastic Packaging Products & Materials   Paper & Plastic Packaging Products & Materials    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.11%   8.11%    
Investment Interest Rate 12.57%   12.57%    
Investment, Acquisition Date Oct. 07, 2022        
Investment Maturity Date Sep. 29, 2028   Sep. 29, 2028    
Investment Owned, Balance, Principal Amount $ 6,521        
Investment Owned, at Cost 6,439        
Investment Owned, at Fair Value $ 6,324        
Fair Value As A Percentage of Member's Equity 18.30%        
Investment, Identifier [Axis]: Maxor Acquisition, Inc. (d/b/a Maxor National Pharmacy Services, LLC) First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MaxorAcquisitionInc.Member        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Health Care Services   Health Care Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 10.46%   10.46%    
Investment, Acquisition Date Dec. 27, 2024        
Investment Maturity Date Mar. 01, 2029   Mar. 01, 2029    
Investment Owned, Balance, Principal Amount $ 947        
Investment Owned, at Cost 938        
Investment Owned, at Fair Value $ 938        
Percent of net assets 0.30%   0.30%    
Investment, Identifier [Axis]: Maxor Acquisition, Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MaxorAcquisitionInc.Member whfcl:MaxorAcquisitionInc.Member      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Services Health Care Services Health Care Services Health Care Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.00% 6.75% 6.00% 6.75%  
Investment Interest Rate 10.46% 12.48% 10.46% 12.48%  
Investment, Acquisition Date Apr. 11, 2023 Apr. 11, 2023      
Investment Maturity Date Mar. 01, 2029 Mar. 01, 2029 Mar. 01, 2029 Mar. 01, 2029  
Investment Owned, at Fair Value $ 9 $ 9      
Investment, Identifier [Axis]: Maxor Acquisition, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MaxorAcquisitionInc.Member whfcl:MaxorAcquisitionInc.Member      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Services Health Care Services Health Care Services Health Care Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.00% 6.75% 6.00% 6.75%  
Investment Interest Rate 10.46% 12.48% 10.46% 12.48%  
Investment, Acquisition Date Apr. 11, 2023 Apr. 11, 2023      
Investment Maturity Date Mar. 01, 2029 Mar. 01, 2029 Mar. 01, 2029 Mar. 01, 2029  
Investment Owned, Balance, Principal Amount $ 5,002 $ 5,053      
Investment Owned, at Cost 4,898 4,922      
Investment Owned, at Fair Value $ 4,986 $ 5,013      
Fair Value As A Percentage of Member's Equity 14.40% 14.50%      
Investment, Identifier [Axis]: Medical Device Inc First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MedicalDeviceIncMember whfcl:MedicalDeviceIncMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Supplies Health Care Supplies Health Care Supplies Health Care Supplies  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.25% 1.00% 1.25% 1.00%  
Spread Above Index 6.25% 6.50% 6.25% 6.50%  
Investment Interest Rate 10.68% 11.95% 10.68% 11.95%  
Investment, Acquisition Date Jul. 27, 2023 Jul. 27, 2023      
Investment Maturity Date Jul. 11, 2029 Jul. 11, 2029 Jul. 11, 2029 Jul. 11, 2029  
Investment Owned, at Fair Value $ 6 $ 3      
Investment, Identifier [Axis]: Medical Device Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MedicalDeviceIncMember whfcl:MedicalDeviceIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Health Care Supplies Health Care Supplies Health Care Supplies Health Care Supplies  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.25% 1.00% 1.25% 1.00%  
Spread Above Index 6.25% 6.50% 6.25% 6.50%  
Investment Interest Rate 10.68% 11.95% 10.68% 11.95%  
Investment, Acquisition Date Jul. 27, 2023 Jul. 27, 2023      
Investment Maturity Date Jul. 11, 2029 Jul. 11, 2029 Jul. 11, 2029 Jul. 11, 2029  
Investment Owned, Balance, Principal Amount $ 2,633 $ 2,660      
Investment Owned, at Cost 2,584 2,599      
Investment Owned, at Fair Value $ 2,660 $ 2,626      
Fair Value As A Percentage of Member's Equity 7.70% 7.60%      
Investment, Identifier [Axis]: Merriman Holdings LP (d/b/a Escalent, Inc.) Class A Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MerrimanHoldingsLPMember whfcl:MerrimanHoldingsLPMember      
Investment, Type [Extensible Enumeration] whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Research & Consulting Services Research & Consulting Services Research & Consulting Services Research & Consulting Services  
Investment, Acquisition Date Apr. 07, 2023 Apr. 07, 2023      
Investment Owned, Balance, Shares | shares 327 327 327 327  
Investment Owned, at Cost $ 333 $ 333      
Investment Owned, at Fair Value $ 368 $ 295      
Percent of net assets 0.10% 0.10% 0.10% 0.10%  
Investment, Identifier [Axis]: Meta Buyer LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MetaBuyerLLCMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Pharmaceuticals   Pharmaceuticals  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.00%   6.00%  
Investment Interest Rate   11.56%   11.56%  
Investment, Acquisition Date   Dec. 16, 2021      
Investment Maturity Date   Nov. 01, 2027   Nov. 01, 2027  
Investment Owned, Balance, Principal Amount   $ 883      
Investment Owned, at Cost   871      
Investment Owned, at Fair Value   $ 883      
Fair Value As A Percentage of Member's Equity   2.50%      
Investment, Identifier [Axis]: Meta Buyer LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MetaBuyerLLCMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Pharmaceuticals   Pharmaceuticals  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.00%   6.00%  
Investment Interest Rate   11.53%   11.53%  
Investment, Acquisition Date   Dec. 16, 2021      
Investment Maturity Date   Nov. 01, 2027   Nov. 01, 2027  
Investment Owned, Balance, Principal Amount   $ 1,156      
Investment Owned, at Cost   1,141      
Investment Owned, at Fair Value   $ 1,161      
Fair Value As A Percentage of Member's Equity   3.30%      
Investment, Identifier [Axis]: Meta Buyer LLC First Lien Secured Term Loan One          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MetaBuyerLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Pharmaceuticals   Pharmaceuticals  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:EuroInterbankOfferedRateMember   whfcl:EuroInterbankOfferedRateMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.00%   6.00%  
Investment Interest Rate   9.87%   9.87%  
Investment, Acquisition Date   Dec. 16, 2021      
Investment Maturity Date   Nov. 01, 2027   Nov. 01, 2027  
Investment Owned, Balance, Principal Amount   $ 12,163      
Investment Owned, at Cost   13,552      
Investment Owned, at Fair Value   $ 13,401      
Fair Value As A Percentage of Member's Equity   38.70%      
Investment, Identifier [Axis]: Meta Buyer LLC First Lien Secured Term Loan Two          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:MetaBuyerLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Pharmaceuticals   Pharmaceuticals  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.00%   6.00%  
Investment Interest Rate   11.46%   11.46%  
Investment, Acquisition Date   Dec. 16, 2021      
Investment Maturity Date   Nov. 01, 2027   Nov. 01, 2027  
Investment Owned, Balance, Principal Amount   $ 971      
Investment Owned, at Cost   959      
Investment Owned, at Fair Value   $ 971      
Fair Value As A Percentage of Member's Equity   2.80%      
Investment, Identifier [Axis]: Meta Buyer LLC., First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MetaBuyerLLCMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Pharmaceuticals   Pharmaceuticals    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 10.51%   10.51%    
Investment, Acquisition Date Dec. 16, 2021        
Investment Maturity Date Nov. 01, 2027   Nov. 01, 2027    
Investment Owned, Balance, Principal Amount $ 874        
Investment Owned, at Cost 865        
Investment Owned, at Fair Value $ 874        
Fair Value As A Percentage of Member's Equity 2.50%        
Investment, Identifier [Axis]: Meta Buyer LLC., First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MetaBuyerLLCMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Pharmaceuticals   Pharmaceuticals    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:EuroInterbankOfferedRateMember   whfcl:EuroInterbankOfferedRateMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 8.85%   8.85%    
Investment, Acquisition Date Dec. 16, 2021        
Investment Maturity Date Nov. 01, 2027   Nov. 01, 2027    
Investment Owned, Balance, Principal Amount $ 12,039        
Investment Owned, at Cost 13,449        
Investment Owned, at Fair Value $ 12,465        
Fair Value As A Percentage of Member's Equity 36.00%        
Investment, Identifier [Axis]: Meta Buyer LLC., First Lien Secured Term Loan One          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MetaBuyerLLCMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Pharmaceuticals   Pharmaceuticals    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 10.48%   10.48%    
Investment, Acquisition Date Dec. 16, 2021        
Investment Maturity Date Nov. 01, 2027   Nov. 01, 2027    
Investment Owned, Balance, Principal Amount $ 962        
Investment Owned, at Cost 952        
Investment Owned, at Fair Value $ 962        
Fair Value As A Percentage of Member's Equity 2.80%        
Investment, Identifier [Axis]: Meta Buyer LLC.,First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MetaBuyerLLCMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Pharmaceuticals   Pharmaceuticals    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 10.44%   10.44%    
Investment, Acquisition Date Dec. 16, 2021        
Investment Maturity Date Nov. 01, 2027   Nov. 01, 2027    
Investment Owned, Balance, Principal Amount $ 1,156        
Investment Owned, at Cost 1,145        
Investment Owned, at Fair Value $ 1,160        
Fair Value As A Percentage of Member's Equity 3.40%        
Investment, Identifier [Axis]: Midwest Texas Tea CA, LLC (d/b/a US Petroleum Partners, LLC) First Lien Secured Bridge Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   Midwest Texas Tea CA, LLC [Member]      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredBridgeLoanMember   whfcl:FirstLienSecuredBridgeLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Distributors   Distributors  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   14.00%   14.00%  
Investment Interest Rate   19.46%   19.46%  
Investment, Acquisition Date   Dec. 22, 2023      
Investment Maturity Date   Dec. 22, 2025   Dec. 22, 2025  
Investment Owned, Balance, Principal Amount   $ 1,464      
Investment Owned, at Cost   1,420      
Investment Owned, at Fair Value   $ 1,420      
Investment, Interest Rate, Paid in Kind   6.00%   6.00%  
Investment, Interest Rate, Paid in Cash   13.46%   13.46%  
Percent of net assets   0.40%   0.40%  
Investment, Identifier [Axis]: Midwest Texas Tea CA, LLC (d/b/a US Petroleum Partners, LLC) First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Midwest Texas Tea CA, LLC [Member] Midwest Texas Tea CA, LLC [Member]      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Distributors Distributors Distributors Distributors  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.25% 7.25% 7.25% 7.25%  
Investment Interest Rate 11.71% 12.71% 11.71% 12.71%  
Investment, Acquisition Date Dec. 22, 2023 Dec. 22, 2023      
Investment Maturity Date Dec. 22, 2028 Dec. 22, 2028 Dec. 22, 2028 Dec. 22, 2028  
Investment Owned, Balance, Principal Amount $ 645        
Investment Owned, at Cost 632        
Investment Owned, at Fair Value $ 642        
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: Midwest Texas Tea CA, LLC (d/b/a US Petroleum Partners, LLC) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Midwest Texas Tea CA, LLC [Member] Midwest Texas Tea CA, LLC [Member]      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Distributors Distributors Distributors Distributors  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Base Rate [Member] whfcl:SecuredOvernightFinancingRateSofrMember Base Rate [Member] whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.92% 7.25% 6.92% 7.25%  
Investment Interest Rate 12.39% 12.71% 12.39% 12.71%  
Investment, Acquisition Date Dec. 22, 2023 Dec. 22, 2023      
Investment Maturity Date Dec. 22, 2028 Dec. 22, 2028 Dec. 22, 2028 Dec. 22, 2028  
Investment Owned, Balance, Principal Amount $ 326        
Investment Owned, at Cost 319        
Investment Owned, at Fair Value $ 328        
Percent of net assets 0.10%   0.10%    
Investment, Identifier [Axis]: Midwest Texas Tea CA, LLC (d/b/a US Petroleum Partners, LLC) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Midwest Texas Tea CA, LLC [Member] Midwest Texas Tea CA, LLC [Member]      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Distributors Distributors Distributors Distributors  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.25% 7.25% 7.25% 7.25%  
Investment Interest Rate 11.71% 12.71% 11.71% 12.71%  
Investment, Acquisition Date Dec. 22, 2023 Dec. 22, 2023      
Investment Maturity Date Dec. 22, 2028 Dec. 22, 2028 Dec. 22, 2028 Dec. 22, 2028  
Investment Owned, Balance, Principal Amount $ 9,443 $ 9,490      
Investment Owned, at Cost 9,255 9,254      
Investment Owned, at Fair Value $ 9,399 $ 9,254      
Percent of net assets 3.30% 2.90% 3.30% 2.90%  
Investment, Identifier [Axis]: Monarch Collective Holdings, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MonarchCollectiveHoldingsLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Real Estate Services   Real Estate Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.50%   1.50%    
Spread Above Index 6.75%   6.75%    
Investment Interest Rate 11.16%   11.16%    
Investment, Acquisition Date Jan. 10, 2024        
Investment Maturity Date Jan. 10, 2029   Jan. 10, 2029    
Investment Owned, Balance, Principal Amount $ 1,596        
Investment Owned, at Cost 1,572        
Investment Owned, at Fair Value $ 1,582        
Percent of net assets 0.60%   0.60%    
Investment, Identifier [Axis]: Monarch Collective Holdings, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MonarchCollectiveHoldingsLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Real Estate Services   Real Estate Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.50%   1.50%    
Spread Above Index 6.75%   6.75%    
Investment Interest Rate 11.08%   11.08%    
Investment, Acquisition Date Jan. 10, 2024        
Investment Maturity Date Jan. 10, 2029   Jan. 10, 2029    
Investment Owned, Balance, Principal Amount $ 9,306        
Investment Owned, at Cost 9,119        
Investment Owned, at Fair Value $ 9,223        
Percent of net assets 3.20%   3.20%    
Investment, Identifier [Axis]: Motivational CIV, LLC Class B Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MotivationalCIVLLCMember whfcl:MotivationalCIVLLCMember      
Investment, Type [Extensible Enumeration] whfcl:ClassBUnitsMember whfcl:ClassBUnitsMember whfcl:ClassBUnitsMember whfcl:ClassBUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics  
Investment, Acquisition Date Jul. 12, 2021 Jul. 12, 2021      
Investment Owned, Balance, Shares | shares 1,250 1,250 1,250 1,250  
Investment Owned, at Cost $ 1,250 $ 1,250      
Investment, Identifier [Axis]: Motivational Marketing, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MotivationalMarketingLLCMember whfcl:MotivationalMarketingLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.50% 7.25% 8.50% 7.25%  
Investment Interest Rate 13.00% 12.71% 13.00% 12.71%  
Investment, Acquisition Date Jul. 12, 2021 Jul. 12, 2021      
Investment Maturity Date Jul. 12, 2026 Jul. 12, 2026 Jul. 12, 2026 Jul. 12, 2026  
Investment Owned, Balance, Principal Amount $ 1,182 $ 473      
Investment Owned, at Cost 1,175 468      
Investment Owned, at Fair Value $ 1,061 $ 338      
Investment, Interest Rate, Paid in Kind 2.00% 0.75% 2.00% 0.75%  
Investment, Interest Rate, Paid in Cash 11.00% 11.96% 11.00% 11.96%  
Percent of net assets 0.40% 0.10% 0.40% 0.10%  
Investment, Identifier [Axis]: Motivational Marketing, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:MotivationalMarketingLLCMember whfcl:MotivationalMarketingLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 8.50% 7.25% 8.50% 7.25%  
Investment Interest Rate 12.96% 12.71% 12.96% 12.71%  
Investment, Acquisition Date Jul. 12, 2021 Jul. 12, 2021      
Investment Maturity Date Jul. 12, 2026 Jul. 12, 2026 Jul. 12, 2026 Jul. 12, 2026  
Investment Owned, Balance, Principal Amount $ 10,510 $ 9,989      
Investment Owned, at Cost 10,449 9,888      
Investment Owned, at Fair Value $ 9,438 $ 8,790      
Investment, Interest Rate, Paid in Kind 7.48% 0.75% 7.48% 0.75%  
Investment, Interest Rate, Paid in Cash 5.48% 11.96% 5.48% 11.96%  
Percent of net assets 3.20% 2.80% 3.20% 2.80%  
Investment, Identifier [Axis]: NNA Services, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:NNAServicesLLCMember whfcl:NNAServicesLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Diversified Support Services Diversified Support Services Diversified Support Services Diversified Support Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.25% 6.75% 7.25% 6.75%  
Investment Interest Rate 11.73% 12.25% 11.73% 12.25%  
Investment, Acquisition Date Aug. 27, 2021 Aug. 27, 2021      
Investment Maturity Date Aug. 27, 2026 Aug. 27, 2026 Aug. 27, 2026 Aug. 27, 2026  
Investment Owned, Balance, Principal Amount $ 9,125 $ 9,417      
Investment Owned, at Cost 9,087 9,354      
Investment Owned, at Fair Value $ 8,941 $ 9,293      
Percent of net assets 3.10% 2.90% 3.10% 2.90%  
Investment, Identifier [Axis]: NPAV Lessor Corp., First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:NPAVLessorCorp.Member whfcl:NPAVLessorCorp.Member      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Real Estate Services Real Estate Services Real Estate Services Real Estate Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 10.96% 11.96% 10.96% 11.96%  
Investment, Acquisition Date Mar. 01, 2022 Mar. 01, 2022      
Investment Maturity Date Jan. 21, 2027 Jan. 21, 2027 Jan. 21, 2027 Jan. 21, 2027  
Investment Owned, Balance, Principal Amount $ 725 $ 725      
Investment Owned, at Cost 719 716      
Investment Owned, at Fair Value $ 660 $ 647      
Fair Value As A Percentage of Member's Equity 1.90% 1.90%      
Investment, Identifier [Axis]: NPAV Lessor Corp., First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:NPAVLessorCorp.Member whfcl:NPAVLessorCorp.Member      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Real Estate Services Real Estate Services Real Estate Services Real Estate Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 10.96% 11.96% 10.96% 11.96%  
Investment, Acquisition Date Mar. 01, 2022 Mar. 01, 2022      
Investment Maturity Date Jan. 21, 2027 Jan. 21, 2027 Jan. 21, 2027 Jan. 21, 2027  
Investment Owned, Balance, Principal Amount $ 6,502 $ 7,510      
Investment Owned, at Cost 6,448 7,418      
Investment Owned, at Fair Value $ 5,918 $ 6,706      
Fair Value As A Percentage of Member's Equity 17.10% 19.30%      
Investment, Identifier [Axis]: Naviga Inc First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:NavigaIncMember whfcl:NavigaIncMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Application Software Application Software Application Software Application Software  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Base Rate [Member] Base Rate [Member] Base Rate [Member] Base Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.84% 6.84% 6.84% 6.84%  
Investment Interest Rate 12.78% 12.78% 12.78% 12.78%  
Investment, Acquisition Date Jun. 14, 2019 Jun. 14, 2019      
Investment Maturity Date Jun. 28, 2024 Feb. 27, 2024 Jun. 28, 2024 Feb. 27, 2024  
Investment Owned, Balance, Principal Amount $ 301 $ 271      
Investment Owned, at Cost 301 271      
Investment Owned, at Fair Value $ 169 $ 268      
Percent of net assets 0.10% 0.10% 0.10% 0.10%  
Investment, Identifier [Axis]: Naviga Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:NavigaIncMember whfcl:NavigaIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Application Software Application Software Application Software Application Software  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.00% 7.00% 7.00% 7.00%  
Investment Interest Rate 12.40% 12.45% 12.40% 12.45%  
Investment, Acquisition Date Jun. 14, 2019 Jun. 14, 2019      
Investment Maturity Date Jun. 28, 2024 Feb. 27, 2024 Jun. 28, 2024 Feb. 27, 2024  
Investment Owned, Balance, Principal Amount $ 3,140 $ 3,148      
Investment Owned, at Cost 3,140 3,148      
Investment Owned, at Fair Value $ 1,763 $ 3,113      
Percent of net assets 0.60% 1.00% 0.60% 1.00%  
Investment, Identifier [Axis]: New American Crafts Holdings, LLC Class A Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:NewAmericanCraftsHoldingsLlcMember whfcl:NewAmericanCraftsHoldingsLlcClassaUnitsMember      
Investment, Type [Extensible Enumeration] whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember whfcl:ClassAUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Acquisition Date Mar. 16, 2023 Mar. 16, 2023      
Investment Owned, Balance, Shares | shares 1 1 1 1  
Investment, Identifier [Axis]: PANOS Brands, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Panos Brands, Llc [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Packaged Foods & Meats   Packaged Foods & Meats    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.15%   10.15%    
Investment, Acquisition Date May 14, 2024        
Investment Maturity Date May 14, 2029   May 14, 2029    
Investment Owned, Balance, Principal Amount $ 27        
Investment Owned, at Cost 27        
Investment Owned, at Fair Value $ 33        
Investment, Identifier [Axis]: PANOS Brands, LLC First Lien Secured Revolving Loan, One 05/14/29          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Panos Brands, Llc [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services   IT Consulting And Other Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.15%   10.15%    
Investment, Acquisition Date Jun. 14, 2024        
Investment Maturity Date May 14, 2029   May 14, 2029    
Investment Owned, Balance, Principal Amount $ 30        
Investment Owned, at Cost 30        
Investment Owned, at Fair Value $ 36        
Fair Value As A Percentage of Member's Equity 0.10%        
Investment, Identifier [Axis]: PANOS Brands, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Panos Brands, Llc [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services   IT Consulting And Other Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.13%   10.13%    
Investment, Acquisition Date Jun. 14, 2024        
Investment Maturity Date May 14, 2029   May 14, 2029    
Investment Owned, Balance, Principal Amount $ 4,520        
Investment Owned, at Cost 4,441        
Investment Owned, at Fair Value $ 4,505        
Fair Value As A Percentage of Member's Equity 13.00%        
Investment, Identifier [Axis]: PANOS Brands, LLC First Lien Secured Term Loan, One 05/14/29          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Panos Brands, Llc [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Packaged Foods & Meats   Packaged Foods & Meats    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.13%   10.13%    
Investment, Acquisition Date May 14, 2024        
Investment Maturity Date May 14, 2029   May 14, 2029    
Investment Owned, Balance, Principal Amount $ 4,068        
Investment Owned, at Cost 3,997        
Investment Owned, at Fair Value $ 4,054        
Percent of net assets 1.40%   1.40%    
Investment, Identifier [Axis]: PFB Holdco, Inc Class A Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:PfbHoldingCompanyLlcMember      
Investment, Type [Extensible Enumeration]   whfcl:ClassAUnitsMember   whfcl:ClassAUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Building Products   Building Products  
Investment, Acquisition Date   Dec. 17, 2021      
Investment Owned, Balance, Shares | shares   1   1  
Investment Owned, at Cost   $ 423      
Investment Owned, at Fair Value   $ 1,053      
Percent of net assets   0.30%   0.30%  
Investment, Identifier [Axis]: PFB Holding Company, LLC Class A Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PFBHoldcoIncMember        
Investment, Type [Extensible Enumeration] whfcl:ClassAUnitsMember   whfcl:ClassAUnitsMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Building Products   Building Products    
Investment, Acquisition Date Dec. 17, 2021        
Investment Owned, Balance, Shares | shares 1   1    
Investment Owned, at Cost $ 24        
Investment, Identifier [Axis]: PG Dental New Jersey Parent, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:PGDentalNewJerseyParentLLCMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Health Care Services   Health Care Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Base Rate [Member]   Base Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.00%   7.00%  
Investment Interest Rate   13.98%   13.98%  
Investment, Acquisition Date   Nov. 25, 2020      
Investment Maturity Date   Nov. 25, 2025   Nov. 25, 2025  
Investment Owned, Balance, Principal Amount   $ 704      
Investment Owned, at Cost   698      
Investment Owned, at Fair Value   $ 704      
Investment, Interest Rate, Paid in Kind   2.25%   2.25%  
Investment, Interest Rate, Paid in Cash   11.73%   11.73%  
Percent of net assets   0.20%   0.20%  
Investment, Identifier [Axis]: PG Dental New Jersey Parent, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:PGDentalNewJerseyParentLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Health Care Services   Health Care Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.50%   7.50%  
Investment Interest Rate   12.96%   12.96%  
Investment, Acquisition Date   Nov. 25, 2020      
Investment Maturity Date   Nov. 25, 2025   Nov. 25, 2025  
Investment Owned, Balance, Principal Amount   $ 6,400      
Investment Owned, at Cost   6,348      
Investment Owned, at Fair Value   $ 6,400      
Investment, Interest Rate, Paid in Kind   2.25%   2.25%  
Investment, Interest Rate, Paid in Cash   10.71%   10.71%  
Percent of net assets   2.00%   2.00%  
Investment, Identifier [Axis]: PLTFRM Companies, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PltfrmCompaniesLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Advertising   Advertising    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 3.00%   3.00%    
Spread Above Index 9.00%   9.00%    
Investment Interest Rate 13.34%   13.34%    
Investment, Acquisition Date Jan. 29, 2024        
Investment Maturity Date Jan. 29, 2029   Jan. 29, 2029    
Investment Owned, Balance, Principal Amount $ 889        
Investment Owned, at Cost 867        
Investment Owned, at Fair Value $ 916        
Investment, Interest Rate, Paid in Kind 1.00%   1.00%    
Investment, Interest Rate, Paid in Cash 12.34%   12.34%    
Percent of net assets 0.30%   0.30%    
Investment, Identifier [Axis]: PLTFRM Companies, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PltfrmCompaniesLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Advertising   Advertising    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 3.00%   3.00%    
Spread Above Index 9.00%   9.00%    
Investment Interest Rate 13.36%   13.36%    
Investment, Acquisition Date Jan. 29, 2024        
Investment Maturity Date Jan. 29, 2029   Jan. 29, 2029    
Investment Owned, Balance, Principal Amount $ 7,950        
Investment Owned, at Cost 7,757        
Investment Owned, at Fair Value $ 8,188        
Investment, Interest Rate, Paid in Kind 1.00%   1.00%    
Investment, Interest Rate, Paid in Cash 12.36%   12.36%    
Percent of net assets 3.00%   3.00%    
Investment, Identifier [Axis]: Patagonia Holdco LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PatagoniaHoldcoLLCMember whfcl:PatagoniaHoldcoLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Integrated Telecommunication Services Integrated Telecommunication Services Integrated Telecommunication Services Integrated Telecommunication Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 0.50% 0.50% 0.50% 0.50%  
Spread Above Index 5.75% 5.75% 5.75% 5.75%  
Investment Interest Rate 10.27% 11.12% 10.27% 11.12%  
Investment, Acquisition Date Aug. 05, 2022 Aug. 05, 2022      
Investment Maturity Date Aug. 01, 2029 Aug. 01, 2029 Aug. 01, 2029 Aug. 01, 2029  
Investment Owned, Balance, Principal Amount $ 14,296 $ 14,442      
Investment Owned, at Cost 12,602 12,357      
Investment Owned, at Fair Value $ 13,135 $ 13,191      
Percent of net assets 4.60% 4.20% 4.60% 4.20%  
Investment, Identifier [Axis]: Pavement Partners Interco, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PavementPartnersIntercoLLCMember whfcl:PavementPartnersIntercoLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering Construction & Engineering Construction & Engineering Construction & Engineering  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.75% 6.75% 6.75% 6.75%  
Investment Interest Rate 11.23% 12.42% 11.23% 12.42%  
Investment, Acquisition Date Mar. 17, 2023 Mar. 17, 2023      
Investment Maturity Date Feb. 07, 2028 Feb. 07, 2028 Feb. 07, 2028 Feb. 07, 2028  
Investment Owned, Balance, Principal Amount $ 569 $ 575      
Investment Owned, at Cost 558 560      
Investment Owned, at Fair Value $ 569 $ 569      
Fair Value As A Percentage of Member's Equity 1.70% 1.60%      
Investment, Identifier [Axis]: Pavement Partners Interco, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PavementPartnersIntercoLLCMember whfcl:PavementPartnersIntercoLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering Construction & Engineering Construction & Engineering Construction & Engineering  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.75% 6.75% 6.75% 6.75%  
Investment Interest Rate 11.23% 12.42% 11.23% 12.42%  
Investment, Acquisition Date Mar. 17, 2023 Mar. 17, 2023      
Investment Maturity Date Feb. 07, 2028 Feb. 07, 2028 Feb. 07, 2028 Feb. 07, 2028  
Investment Owned, Balance, Principal Amount $ 338        
Investment Owned, at Cost 331        
Investment Owned, at Fair Value $ 341 $ 5      
Fair Value As A Percentage of Member's Equity 1.00%        
Investment, Identifier [Axis]: Pavement Partners Interco, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PavementPartnersIntercoLLCMember whfcl:PavementPartnersIntercoLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering Construction & Engineering Construction & Engineering Construction & Engineering  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.75% 6.75% 6.75% 6.75%  
Investment Interest Rate 11.23% 12.27% 11.23% 12.27%  
Investment, Acquisition Date Mar. 17, 2023 Mar. 17, 2023      
Investment Maturity Date Feb. 07, 2028 Feb. 07, 2028 Feb. 07, 2028 Feb. 07, 2028  
Investment Owned, Balance, Principal Amount $ 5,117 $ 4,455      
Investment Owned, at Cost 5,015 4,344      
Investment Owned, at Fair Value $ 5,111 $ 4,405      
Fair Value As A Percentage of Member's Equity 14.80% 12.70%      
Investment, Identifier [Axis]: Pennsylvania Machine Works, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:PennsylvaniaMachineWorksLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Industrial Machinery & Supplies & Components   Industrial Machinery & Supplies & Components  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.00%   6.00%  
Investment Interest Rate   11.61%   11.61%  
Investment, Acquisition Date   Mar. 25, 2022      
Investment Maturity Date   Mar. 08, 2027   Mar. 08, 2027  
Investment Owned, Balance, Principal Amount   $ 6,561      
Investment Owned, at Cost   6,498      
Investment Owned, at Fair Value   $ 6,561      
Fair Value As A Percentage of Member's Equity   18.90%      
Investment, Identifier [Axis]: Pirtek Holdco, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PirtekHoldcoLLCMember whfcl:PirtekHoldcoLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Diversified Support Services Diversified Support Services Diversified Support Services Diversified Support Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.50% 5.75% 5.50% 5.75%  
Investment Interest Rate 9.95% 11.20% 9.95% 11.20%  
Investment, Acquisition Date Oct. 31, 2023 Oct. 31, 2023      
Investment Maturity Date Oct. 26, 2028 Oct. 26, 2028 Oct. 26, 2028 Oct. 26, 2028  
Investment Owned, at Fair Value $ 17        
Investment, Identifier [Axis]: Pirtek Holdco, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PirtekHoldcoLLCMember whfcl:PirtekHoldcoLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Diversified Support Services Diversified Support Services Diversified Support Services Diversified Support Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.50% 5.75% 5.50% 5.75%  
Investment Interest Rate 9.95% 11.20% 9.95% 11.20%  
Investment, Acquisition Date Oct. 31, 2023 Oct. 31, 2023      
Investment Maturity Date Oct. 26, 2028 Oct. 26, 2028 Oct. 26, 2028 Oct. 26, 2028  
Investment Owned, Balance, Principal Amount $ 7,425 $ 7,500      
Investment Owned, at Cost 7,298 7,337      
Investment Owned, at Fair Value $ 7,425 $ 7,337      
Fair Value As A Percentage of Member's Equity 21.50% 21.20%      
Investment, Identifier [Axis]: PlayMonster LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:PlaymonsterGroupLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment Owned, at Fair Value   $ 1,363     2,977
Investment, Identifier [Axis]: Playmonster Group Equity, Inc Common Stock          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PlaymonsterGroupEquityIncMember whfcl:PlaymonsterGroupEquityIncMember      
Investment, Type [Extensible Enumeration] Common Stock [Member] Common Stock [Member] Common Stock [Member] Common Stock [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Acquisition Date Jan. 24, 2022 Jan. 24, 2022      
Investment Owned, Balance, Shares | shares 72 72 72 72  
Investment Owned, at Cost $ 460 $ 460      
Investment, Identifier [Axis]: Playmonster Group Equity, Inc. Preferred Stock          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PlaymonsterGroupEquityIncMember whfcl:PlaymonsterGroupEquityIncMember      
Investment, Type [Extensible Enumeration] us-gaap:PreferredStockMember us-gaap:PreferredStockMember us-gaap:PreferredStockMember us-gaap:PreferredStockMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment Interest Rate 14.00% 14.00% 14.00% 14.00%  
Investment, Acquisition Date Jan. 24, 2022 Jan. 24, 2022      
Investment Owned, Balance, Shares | shares 36 36 36 36  
Investment Owned, at Cost $ 3,600 $ 3,600      
Investment, Interest Rate, Paid in Kind 14.00% 14.00% 14.00% 14.00%  
Investment, Identifier [Axis]: Playmonster Group LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PlaymonsterGroupLLCMember whfcl:PlayMonsterLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 9.00% 9.00% 9.00% 9.00%  
Investment, Acquisition Date Jun. 07, 2021 Jun. 07, 2021      
Investment Maturity Date Jun. 08, 2026 Jun. 08, 2026 Jun. 08, 2026 Jun. 08, 2026  
Investment Owned, Balance, Principal Amount $ 4,890 $ 4,232      
Investment Owned, at Cost 3,661 3,661      
Investment Owned, at Fair Value $ 1,635 $ 1,363      
Investment, Interest Rate, Paid in Kind 13.74% 14.53% 13.74% 14.53%  
Percent of net assets 0.60% 0.40% 0.60% 0.40%  
Investment, Identifier [Axis]: Playmonster Group LLC, Priority First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PlaymonsterGroupLLCMember whfcl:PlayMonsterLLCMember      
Investment, Type [Extensible Enumeration] whfcl:PriorityFirstLienSecuredTermLoanMember whfcl:PriorityFirstLienSecuredTermLoanMember whfcl:PriorityFirstLienSecuredTermLoanMember whfcl:PriorityFirstLienSecuredTermLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Products Leisure Products Leisure Products Leisure Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.75% 6.75% 6.75% 6.75%  
Investment, Acquisition Date Dec. 09, 2022 Dec. 09, 2022      
Investment Maturity Date Jun. 08, 2026 Jun. 08, 2026 Jun. 08, 2026 Jun. 08, 2026  
Investment Owned, Balance, Principal Amount $ 1,289 $ 1,140      
Investment Owned, at Cost 1,275 1,118      
Investment Owned, at Fair Value $ 1,172 $ 1,015     176
Investment, Interest Rate, Paid in Kind 11.41% 12.37% 11.41% 12.37%  
Percent of net assets 0.40% 0.30% 0.40% 0.30%  
Investment, Identifier [Axis]: Potpourri Group, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:PotpourriGroupIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Broadline Retail   Broadline Retail  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.50%   1.50%  
Spread Above Index   8.25%   8.25%  
Investment Interest Rate   13.71%   13.71%  
Investment, Acquisition Date   Jul. 03, 2019      
Investment Maturity Date   Jul. 03, 2024   Jul. 03, 2024  
Investment Owned, Balance, Principal Amount   $ 13,799      
Investment Owned, at Cost   13,767      
Investment Owned, at Fair Value   $ 13,799      
Percent of net assets   4.40%   4.40%  
Investment, Identifier [Axis]: Poultry Holdings LLC., First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:PoultryHoldingsLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Packaged Foods & Meats   Packaged Foods & Meats  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment, Acquisition Date   Oct. 21, 2019      
Investment Maturity Date   Jun. 28, 2025   Jun. 28, 2025  
Investment Owned, Balance, Principal Amount   $ 6,939      
Investment Owned, at Cost   6,904      
Investment Owned, at Fair Value   $ 6,904      
Fair Value As A Percentage of Member's Equity   19.90%      
Investment, Identifier [Axis]: Power Service Group CR Acquisition Inc First Lien Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PowerServiceGroupCrAcquisitionIncMember whfcl:PowerServiceGroupCrAcquisitionIncMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Heavy Electrical Equipment [Member] Heavy Electrical Equipment [Member] Heavy Electrical Equipment [Member] Heavy Electrical Equipment [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.75% 6.75% 6.75% 6.75%  
Investment Interest Rate 11.23% 12.25% 11.23% 12.25%  
Investment, Acquisition Date Jul. 11, 2022 Jul. 11, 2022      
Investment Maturity Date Jun. 25, 2026 Jun. 25, 2026 Jun. 25, 2026 Jun. 25, 2026  
Investment Owned, Balance, Principal Amount $ 1,340 $ 1,356      
Investment Owned, at Cost 1,329 1,336      
Investment Owned, at Fair Value $ 1,354 $ 1,353      
Percent of net assets 0.50% 0.40% 0.50% 0.40%  
Investment, Identifier [Axis]: Power Service Group CR Acquisition Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PowerServiceGroupCrAcquisitionIncMember whfcl:PowerServiceGroupCrAcquisitionIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Heavy Electrical Equipment [Member] Heavy Electrical Equipment [Member] Heavy Electrical Equipment [Member] Heavy Electrical Equipment [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.75% 6.75% 6.75% 6.75%  
Investment Interest Rate 11.23% 12.25% 11.23% 12.25%  
Investment, Acquisition Date Jun. 25, 2021 Jun. 25, 2021      
Investment Maturity Date Jun. 25, 2026 Jun. 25, 2026 Jun. 25, 2026 Jun. 25, 2026  
Investment Owned, Balance, Principal Amount $ 8,697 $ 8,804      
Investment Owned, at Cost 8,642 8,712      
Investment Owned, at Fair Value $ 8,784 $ 8,782      
Percent of net assets 3.10% 2.80% 3.10% 2.80%  
Investment, Identifier [Axis]: Pressurized Holdings, LLC Common Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Pressurized Holdings, LLC [Member] Pressurized Holdings, LLC [Member]      
Investment, Type [Extensible Enumeration] whfcl:CommonUnitsMember whfcl:CommonUnitsMember whfcl:CommonUnitsMember whfcl:CommonUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Diversified Chemicals [Member] Diversified Chemicals [Member] Diversified Chemicals [Member] Diversified Chemicals [Member]  
Investment, Acquisition Date Mar. 16, 2023 Mar. 16, 2023      
Investment, Identifier [Axis]: Pressurized Holdings, LLC Preferred Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Pressurized Holdings, LLC [Member] Pressurized Holdings, LLC [Member]      
Investment, Type [Extensible Enumeration] Preferred Units [Member] Preferred Units [Member] Preferred Units [Member] Preferred Units [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Diversified Chemicals [Member] Diversified Chemicals [Member] Diversified Chemicals [Member] Diversified Chemicals [Member]  
Investment Interest Rate 14.00%   14.00%    
Investment, Acquisition Date Mar. 16, 2023 Mar. 16, 2023      
Investment Owned, at Cost $ 4,537 $ 4,537      
Investment Owned, at Fair Value $ 1,657 $ 251      
Investment, Interest Rate, Paid in Kind 14.00% 14.00% 14.00% 14.00%  
Percent of net assets 0.60% 0.10% 0.60% 0.10%  
Investment, Identifier [Axis]: Principal Lighting Group, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PrincipalLightingGroupLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Electronic Equipment & Instruments   Electronic Equipment & Instruments    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.25%   5.25%    
Investment Interest Rate 9.81%   9.81%    
Investment, Acquisition Date Dec. 03, 2024        
Investment Maturity Date Nov. 04, 2030   Nov. 04, 2030    
Investment, Identifier [Axis]: Principal Lighting Group, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:PrincipalLightingGroupLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Electronic Equipment & Instruments   Electronic Equipment & Instruments    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.25%   5.25%    
Investment Interest Rate 9.81%   9.81%    
Investment, Acquisition Date Dec. 03, 2024        
Investment Maturity Date Nov. 04, 2030   Nov. 04, 2030    
Investment Owned, Balance, Principal Amount $ 3,531        
Investment Owned, at Cost 3,479        
Investment Owned, at Fair Value $ 3,479        
Fair Value As A Percentage of Member's Equity 10.10%        
Investment, Identifier [Axis]: Project Castle, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:ProjectCastleIncMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Industrial Machinery & Supplies & Components   Industrial Machinery & Supplies & Components  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   0.50%   0.50%  
Spread Above Index   5.50%   5.50%  
Investment Interest Rate   10.89%   10.89%  
Investment, Acquisition Date   Jun. 09, 2022      
Investment Maturity Date   Jun. 01, 2029   Jun. 01, 2029  
Investment Owned, Balance, Principal Amount   $ 6,027      
Investment Owned, at Cost   5,536      
Investment Owned, at Fair Value   $ 5,364      
Percent of net assets   1.70%   1.70%  
Investment, Identifier [Axis]: Quest Events LLC, First Lien Secured Term Loan, 09/30/26          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:QuestEventsLLCMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Diversified Support Services   Diversified Support Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 2.00%   2.00%    
Spread Above Index 7.00%   7.00%    
Investment Interest Rate 11.59%   11.59%    
Investment, Acquisition Date Jul. 19, 2019        
Investment Maturity Date Sep. 30, 2026   Sep. 30, 2026    
Investment Owned, Balance, Principal Amount $ 11,592        
Investment Owned, at Cost 11,563        
Investment Owned, at Fair Value $ 11,592        
Fair Value As A Percentage of Member's Equity 33.50%        
Investment, Identifier [Axis]: Quest Events, LLC Common Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:QuestEventsLLCMember whfcl:QuestEventsLLCMember      
Investment, Type [Extensible Enumeration] whfcl:CommonUnitsMember whfcl:CommonUnitsMember whfcl:CommonUnitsMember whfcl:CommonUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Diversified Support Services Diversified Support Services Diversified Support Services Diversified Support Services  
Investment, Acquisition Date Dec. 28, 2018 Dec. 28, 2018      
Investment Owned, Balance, Shares | shares 333 317 333 317  
Investment Owned, at Cost $ 376 $ 360      
Investment Owned, at Fair Value $ 149 $ 305      
Percent of net assets 0.10% 0.10% 0.10% 0.10%  
Investment, Identifier [Axis]: Quest Events, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:QuestEventsLLCMember whfcl:QuestEventsLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Diversified Support Services Diversified Support Services Diversified Support Services Diversified Support Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 2.00% 2.00% 2.00% 2.00%  
Spread Above Index 7.00% 7.25% 7.00% 7.25%  
Investment Interest Rate 11.59% 12.86% 11.59% 12.86%  
Investment, Acquisition Date Jul. 19, 2019 Jul. 19, 2019      
Investment Maturity Date Sep. 30, 2026 Sep. 30, 2026 Sep. 30, 2026 Sep. 30, 2026  
Investment Owned, Balance, Principal Amount $ 247 $ 247      
Investment Owned, at Cost 246 246      
Investment Owned, at Fair Value $ 248 $ 242      
Fair Value As A Percentage of Member's Equity 0.70% 0.70%      
Investment, Identifier [Axis]: Quest Events, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:QuestEventsLLCMember whfcl:QuestEventsLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Diversified Support Services Diversified Support Services Diversified Support Services Diversified Support Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] whfcl:SecuredOvernightFinancingRateSofrMember Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 2.00% 1.00% 2.00%  
Spread Above Index 6.50% 7.25% 6.50% 7.25%  
Investment Interest Rate 10.90% 12.86% 10.90% 12.86%  
Investment, Acquisition Date Sep. 13, 2024 Jul. 19, 2019      
Investment Maturity Date Sep. 30, 2026 Sep. 30, 2026 Sep. 30, 2026 Sep. 30, 2026  
Investment Owned, Balance, Principal Amount $ 480 $ 11,709      
Investment Owned, at Cost 472 11,663      
Investment Owned, at Fair Value $ 473 $ 11,557      
Fair Value As A Percentage of Member's Equity   33.30%      
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: RCKC Acquisitions LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:RCKCAcquisitionsLLCMember whfcl:RCKCAcquisitionsLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.25% 6.00% 5.25% 6.00%  
Investment Interest Rate 9.99% 11.53% 9.99% 11.53%  
Investment, Acquisition Date Jan. 27, 2021 Jan. 27, 2021      
Investment Maturity Date Jan. 02, 2029 Dec. 31, 2026 Jan. 02, 2029 Dec. 31, 2026  
Investment Owned, Balance, Principal Amount $ 2,946 $ 2,976      
Investment Owned, at Cost 2,922 2,945      
Investment Owned, at Fair Value $ 2,946 $ 2,965      
Fair Value As A Percentage of Member's Equity 8.50% 8.60%      
Investment, Identifier [Axis]: RCKC Acquisitions LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:RCKCAcquisitionsLLCMember whfcl:RCKCAcquisitionsLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.25% 6.00% 5.25% 6.00%  
Investment Interest Rate 9.73% 11.50% 9.73% 11.50%  
Investment, Acquisition Date Jan. 27, 2021 Jan. 27, 2021      
Investment Maturity Date Jan. 02, 2029 Dec. 31, 2026 Jan. 02, 2029 Dec. 31, 2026  
Investment Owned, Balance, Principal Amount $ 10,923 $ 11,036      
Investment Owned, at Cost 10,839 10,925      
Investment Owned, at Fair Value $ 10,923 $ 10,993      
Fair Value As A Percentage of Member's Equity 31.60% 31.70%      
Investment, Identifier [Axis]: RCKC Acquisitions LLC, First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:RCKCAcquisitionsLLCMember whfcl:RCKCAcquisitionsLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.25% 6.00% 5.25% 6.00%  
Investment Interest Rate 9.99% 11.58% 9.99% 11.58%  
Investment, Acquisition Date Jan. 27, 2021 Jan. 27, 2021      
Investment Maturity Date Jan. 02, 2029 Dec. 31, 2026 Jan. 02, 2029 Dec. 31, 2026  
Investment Owned, Balance, Principal Amount   $ 107      
Investment Owned, at Cost   106      
Investment Owned, at Fair Value $ 11 $ 114      
Fair Value As A Percentage of Member's Equity   0.30%      
Investment, Identifier [Axis]: RLJ Pro-Vac, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:RLJPro-VacInc.Member        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Environmental & Facilities Services   Environmental & Facilities Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.25%   6.25%    
Investment Interest Rate 10.71%   10.71%    
Investment, Acquisition Date Jan. 23, 2024        
Investment Maturity Date Dec. 31, 2026   Dec. 31, 2026    
Investment Owned, Balance, Principal Amount $ 6,659        
Investment Owned, at Cost 6,566        
Investment Owned, at Fair Value $ 6,637        
Fair Value As A Percentage of Member's Equity 19.20%        
Investment, Identifier [Axis]: Ribbon Communications Operating Company, Inc. (d/b/a Ribbon Communications Inc.) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Ribbon Communications Operating Company, Inc. [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Systems Software   Systems Software    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.25%   6.25%    
Investment Interest Rate 10.59%   10.59%    
Investment, Acquisition Date Jun. 21, 2024        
Investment Maturity Date Jun. 21, 2029   Jun. 21, 2029    
Investment Owned, at Fair Value $ 9        
Investment, Identifier [Axis]: Ribbon Communications Operating Company, Inc. (d/b/a Ribbon Communications Inc.) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Ribbon Communications Operating Company, Inc. [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Systems Software   Systems Software    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.25%   6.25%    
Investment Interest Rate 10.59%   10.59%    
Investment, Acquisition Date Jun. 21, 2024        
Investment Maturity Date Jun. 21, 2029   Jun. 21, 2029    
Investment Owned, Balance, Principal Amount $ 8,756        
Investment Owned, at Cost 8,600        
Investment Owned, at Fair Value $ 8,692        
Percent of net assets 3.00%   3.00%    
Investment, Identifier [Axis]: Ross-Simons Topco, LP Preferred Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:Ross-SimonsTopcoLPMember whfcl:Ross-SimonsTopcoLPMember      
Investment, Type [Extensible Enumeration] Preferred Units [Member] Preferred Units [Member] Preferred Units [Member] Preferred Units [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Broadline Retail Broadline Retail Broadline Retail Broadline Retail  
Investment Interest Rate 8.00% 8.00% 8.00% 8.00%  
Investment, Acquisition Date Dec. 04, 2020 Dec. 04, 2020      
Investment Owned, Balance, Shares | shares 600 600 600 600  
Investment Owned, at Cost $ 514 $ 514      
Investment Owned, at Fair Value $ 756 $ 832      
Investment, Interest Rate, Paid in Kind 8.00% 8.00% 8.00% 8.00%  
Percent of net assets 0.30% 0.30% 0.30% 0.30%  
Investment, Identifier [Axis]: SFS Global Holding Company Warrants          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SFSGlobalHoldingCompanyMember      
Investment, Type [Extensible Enumeration]   Warrant [Member]   Warrant [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Other Diversified Financial Services [Member]   Other Diversified Financial Services [Member]  
Investment, Acquisition Date   Jun. 28, 2018      
Investment Maturity Date   Dec. 28, 2025   Dec. 28, 2025  
Investment, Identifier [Axis]: Salon Republic Holdings, LLC (d/b/a Salon Republic, LLC) First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SalonRepublicHoldingsLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Specialized Consumer Services [Member]   Specialized Consumer Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.00%   8.00%    
Investment Interest Rate 12.46%   12.46%    
Investment, Acquisition Date Dec. 02, 2022        
Investment Maturity Date Dec. 02, 2027   Dec. 02, 2027    
Investment Owned, Balance, Principal Amount $ 1,669        
Investment Owned, at Cost 1,641        
Investment Owned, at Fair Value $ 1,672        
Percent of net assets 0.60%   0.60%    
Investment, Identifier [Axis]: Salon Republic Holdings, LLC (d/b/a Salon Republic, LLC) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SalonRepublicHoldingsLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Specialized Consumer Services [Member]   Specialized Consumer Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.00%   8.00%    
Investment Interest Rate 12.46%   12.46%    
Investment, Acquisition Date Dec. 02, 2022        
Investment Maturity Date Dec. 02, 2027   Dec. 02, 2027    
Investment Owned, at Fair Value $ 13        
Investment, Identifier [Axis]: Salon Republic Holdings, LLC (d/b/a Salon Republic, LLC) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SalonRepublicHoldingsLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Specialized Consumer Services [Member]   Specialized Consumer Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 8.00%   8.00%    
Investment Interest Rate 12.46%   12.46%    
Investment, Acquisition Date Dec. 02, 2022        
Investment Maturity Date Dec. 02, 2027   Dec. 02, 2027    
Investment Owned, Balance, Principal Amount $ 5,076        
Investment Owned, at Cost 4,988        
Investment Owned, at Fair Value $ 5,063        
Percent of net assets 1.80%   1.80%    
Investment, Identifier [Axis]: Salon Republic Holdings, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SalonRepublicHoldingsLlcMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.50%   7.50%  
Investment Interest Rate   12.96%   12.96%  
Investment, Acquisition Date   Dec. 02, 2022      
Investment Maturity Date   Dec. 02, 2027   Dec. 02, 2027  
Investment Owned, Balance, Principal Amount   $ 741      
Investment Owned, at Cost   729      
Investment Owned, at Fair Value   $ 745      
Percent of net assets   0.20%   0.20%  
Investment, Identifier [Axis]: Salon Republic Holdings, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SalonRepublicHoldingsLlcMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Spread Above Index   7.50%   7.50%  
Investment Interest Rate   12.96%   12.96%  
Investment, Acquisition Date   Dec. 02, 2022      
Investment Maturity Date   Dec. 02, 2027   Dec. 02, 2027  
Investment Owned, Balance, Principal Amount   $ 251      
Investment Owned, at Cost   245      
Investment Owned, at Fair Value   $ 258      
Percent of net assets   0.10%   0.10%  
Investment, Identifier [Axis]: Salon Republic Holdings, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SalonRepublicHoldingsLlcMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.50%   7.50%  
Investment Interest Rate   12.96%   12.96%  
Investment, Acquisition Date   Dec. 02, 2022      
Investment Maturity Date   Dec. 02, 2027   Dec. 02, 2027  
Investment Owned, Balance, Principal Amount   $ 5,121      
Investment Owned, at Cost   5,001      
Investment Owned, at Fair Value   $ 5,077      
Percent of net assets   1.60%   1.60%  
Investment, Identifier [Axis]: Salon Republic Investments LLC Common Stock          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SalonRepublicInvestmentsLlcMember      
Investment, Type [Extensible Enumeration]   Common Stock [Member]   Common Stock [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Specialized Consumer Services [Member]   Specialized Consumer Services [Member]  
Investment, Acquisition Date   Dec. 02, 2022      
Investment Owned, Balance, Shares | shares   400   400  
Investment Owned, at Cost   $ 400      
Investment Owned, at Fair Value   $ 241      
Percent of net assets   0.10%   0.10%  
Investment, Identifier [Axis]: Salon Republic Investments LLC Preferred Stock          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SalonRepublicInvestmentsLlcMember      
Investment, Type [Extensible Enumeration]   us-gaap:PreferredStockMember   us-gaap:PreferredStockMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Specialized Consumer Services [Member]   Specialized Consumer Services [Member]  
Investment, Acquisition Date   Dec. 02, 2022      
Investment Owned, Balance, Shares | shares   200   200  
Investment Owned, at Cost   $ 200      
Investment Owned, at Fair Value   $ 218      
Investment, Interest Rate, Paid in Kind   8.00%   8.00%  
Percent of net assets   0.10%   0.10%  
Investment, Identifier [Axis]: Salon Republic Investments LLC, Common Stock          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SalonRepublicInvestmentsLlcMember        
Investment, Type [Extensible Enumeration] Common Stock [Member]   Common Stock [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Real Estate Operating Companies   Real Estate Operating Companies    
Investment, Acquisition Date Dec. 02, 2022        
Investment Owned, Balance, Shares | shares 400   400    
Investment Owned, at Cost $ 400        
Investment Owned, at Fair Value $ 132        
Investment, Identifier [Axis]: Salon Republic Investments LLC, Preferred Stock          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SalonRepublicInvestmentsLlcMember        
Investment, Type [Extensible Enumeration] us-gaap:PreferredStockMember   us-gaap:PreferredStockMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Real Estate Operating Companies   Real Estate Operating Companies    
Investment Interest Rate 8.00%   8.00%    
Investment, Acquisition Date Dec. 02, 2022        
Investment Owned, Balance, Shares | shares 200   200    
Investment Owned, at Cost $ 200        
Investment Owned, at Fair Value $ 242        
Investment, Interest Rate, Paid in Kind 8.00%   8.00%    
Percent of net assets 0.10%   0.10%    
Investment, Identifier [Axis]: Sigue Corporation Warrants          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SigueCorporationMember      
Investment, Type [Extensible Enumeration]   Warrant [Member]   Warrant [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Other Diversified Financial Services [Member]   Other Diversified Financial Services [Member]  
Investment, Acquisition Date   Jun. 28, 2018      
Investment Maturity Date   Dec. 28, 2025   Dec. 28, 2025  
Investment Owned, Balance, Shares | shares   22   22  
Investment Owned, at Cost   $ 2,890      
Investment Owned, at Fair Value   $ 3,472      
Percent of net assets   1.10%   1.10%  
Investment, Identifier [Axis]: Sleep OpCo LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SleepOpCoLLCMember whfcl:SleepOpCoLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Home Furnishings [Member] Home Furnishings [Member] Home Furnishings [Member] Home Furnishings [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 11.28% 12.07% 11.28% 12.07%  
Investment, Acquisition Date Oct. 12, 2021 Oct. 12, 2021      
Investment Maturity Date Oct. 12, 2026 Oct. 12, 2026 Oct. 12, 2026 Oct. 12, 2026  
Investment Owned, at Fair Value $ 5 $ 3      
Investment, Identifier [Axis]: Sleep OpCo LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SleepOpCoLLCMember whfcl:SleepOpCoLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Home Furnishings [Member] Home Furnishings [Member] Home Furnishings [Member] Home Furnishings [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 11.28% 12.07% 11.28% 12.07%  
Investment, Acquisition Date Oct. 12, 2021 Oct. 12, 2021      
Investment Maturity Date Oct. 12, 2026 Oct. 12, 2026 Oct. 12, 2026 Oct. 12, 2026  
Investment Owned, Balance, Principal Amount $ 22,590 $ 20,616      
Investment Owned, at Cost 22,401 20,385      
Investment Owned, at Fair Value $ 22,441 $ 20,407      
Percent of net assets 7.80% 6.40% 7.80% 6.40%  
Investment, Identifier [Axis]: Smalto Inc, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SmaltoInc.Member        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Household Appliances   Household Appliances    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:EuroInterbankOfferedRateMember   whfcl:EuroInterbankOfferedRateMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 8.86%   8.86%    
Investment, Acquisition Date May 04, 2022        
Investment Maturity Date Apr. 28, 2028   Apr. 28, 2028    
Investment Owned, Balance, Principal Amount $ 6,423        
Investment Owned, at Cost 6,682        
Investment Owned, at Fair Value $ 6,654        
Fair Value As A Percentage of Member's Equity 19.20%        
Investment, Identifier [Axis]: Smalto Inc, First Lien Secured Term Loan Interest Rate 10.18          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SmaltoInc.Member      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Household Appliances   Household Appliances  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:EuroInterbankOfferedRateMember   whfcl:EuroInterbankOfferedRateMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.25%   6.25%  
Investment Interest Rate   10.18%   10.18%  
Investment, Acquisition Date   May 04, 2022      
Investment Maturity Date   Apr. 28, 2028   Apr. 28, 2028  
Investment Owned, Balance, Principal Amount   $ 6,576      
Investment Owned, at Cost   6,821      
Investment Owned, at Fair Value   $ 7,172      
Fair Value As A Percentage of Member's Equity   20.70%      
Investment, Identifier [Axis]: Smalto Inc, First Lien Secured Term Loan Interest Rate 11.50          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SmaltoInc.Member      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Household Appliances   Household Appliances  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.00%   6.00%  
Investment Interest Rate   11.50%   11.50%  
Investment, Acquisition Date   May 04, 2022      
Investment Maturity Date   Apr. 28, 2028   Apr. 28, 2028  
Investment Owned, Balance, Principal Amount   $ 1,001      
Investment Owned, at Cost   987      
Investment Owned, at Fair Value   $ 996      
Fair Value As A Percentage of Member's Equity   2.90%      
Investment, Identifier [Axis]: Smalto Inc, First Lien Secured Term Loan One          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SmaltoInc.Member        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Household Appliances   Household Appliances    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.21%   10.21%    
Investment, Acquisition Date May 04, 2022        
Investment Maturity Date Apr. 28, 2028   Apr. 28, 2028    
Investment Owned, Balance, Principal Amount $ 978        
Investment Owned, at Cost 967        
Investment Owned, at Fair Value $ 978        
Fair Value As A Percentage of Member's Equity 2.80%        
Investment, Identifier [Axis]: Snap Fitness Holdings, Inc Class A Common Stock          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SnapFitnessHoldingsIncMember whfcl:SnapFitnessHoldingsIncMember      
Investment, Type [Extensible Enumeration] us-gaap:CommonClassAMember us-gaap:CommonClassAMember us-gaap:CommonClassAMember us-gaap:CommonClassAMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member]  
Investment, Acquisition Date Jun. 29, 2020 Jun. 29, 2020      
Investment Owned, Balance, Shares | shares 2 2 2 2  
Investment Owned, at Cost $ 1,941 $ 1,941      
Investment Owned, at Fair Value $ 173 $ 130      
Percent of net assets 0.10%   0.10%    
Investment, Identifier [Axis]: Snap Fitness Holdings, Inc First Lien Secured Term Loan C          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SnapFitnessHoldingsIncMember whfcl:SnapFitnessHoldingsIncMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredTermLoanCMember whfcl:FirstLienSecuredTermLoanCMember whfcl:FirstLienSecuredTermLoanCMember whfcl:FirstLienSecuredTermLoanCMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member]  
Investment Interest Rate 9.50% 9.50% 9.50% 9.50%  
Investment, Acquisition Date Jun. 29, 2020 Jun. 29, 2020      
Investment Owned, Balance, Principal Amount $ 1,822 $ 1,657      
Investment Owned, at Cost 1,819 1,654      
Investment Owned, at Fair Value $ 1,790 $ 1,623      
Investment, Interest Rate, Paid in Kind   9.50%   9.50%  
Percent of net assets 0.60% 0.50% 0.60% 0.50%  
Investment, Identifier [Axis]: Snap Fitness Holdings, Inc Warrants          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SnapFitnessHoldingsIncMember whfcl:SnapFitnessHoldingsIncMember      
Investment, Type [Extensible Enumeration] Warrant [Member] Warrant [Member] Warrant [Member] Warrant [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member] Leisure Facilities [Member]  
Investment, Acquisition Date Jun. 29, 2020 Jun. 29, 2020      
Investment Owned, Balance, Shares | shares 1 1 1 1  
Investment Owned, at Cost $ 793 $ 793      
Investment Owned, at Fair Value $ 70 $ 53      
Investment, Identifier [Axis]: Solar Holdings Bidco Limited First Lien Secured Term Loan CDOR          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SolarHoldingsBidcoLimitedMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:CanadianDollarOfferedRateMember   whfcl:CanadianDollarOfferedRateMember  
Investment, Interest Rate, Floor   0.50%   0.50%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.94%   11.94%  
Investment, Acquisition Date   Mar. 23, 2023      
Investment Maturity Date   Sep. 28, 2029   Sep. 28, 2029  
Investment Owned, Balance, Principal Amount   $ 3,873      
Investment Owned, at Cost   2,759      
Investment Owned, at Fair Value   $ 2,892      
Fair Value As A Percentage of Member's Equity   8.30%      
Investment, Identifier [Axis]: Solar Holdings Bidco Limited First Lien Secured Term Loan SOFR          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SolarHoldingsBidcoLimitedMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   0.50%   0.50%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.85%   11.85%  
Investment, Acquisition Date   Mar. 23, 2023      
Investment Maturity Date   Sep. 28, 2029   Sep. 28, 2029  
Investment Owned, Balance, Principal Amount   $ 2,807      
Investment Owned, at Cost   2,744      
Investment Owned, at Fair Value   $ 2,786      
Fair Value As A Percentage of Member's Equity   8.00%      
Investment, Identifier [Axis]: Solar Holdings Bidco Limited First Lien Secured Term Loan SONIA          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SolarHoldingsBidcoLimitedMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Sterling Overnight Index Average [Member]   Sterling Overnight Index Average [Member]  
Investment, Interest Rate, Floor   0.00%   0.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.72%   11.72%  
Investment, Acquisition Date   Mar. 23, 2023      
Investment Maturity Date   Sep. 28, 2029   Sep. 28, 2029  
Investment Owned, Balance, Principal Amount   $ 171      
Investment Owned, at Cost   205      
Investment Owned, at Fair Value   $ 217      
Fair Value As A Percentage of Member's Equity   0.60%      
Investment, Identifier [Axis]: Solar Holdings Bidco Limited, First Lien Secured Delayed Draw Loan CDOR          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SolarHoldingsBidcoLimitedMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:CanadianDollarOfferedRateMember   whfcl:CanadianDollarOfferedRateMember  
Investment, Interest Rate, Floor   0.50%   0.50%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   12.08%   12.08%  
Investment, Acquisition Date   Mar. 23, 2023      
Investment Maturity Date   Sep. 28, 2029   Sep. 28, 2029  
Investment Owned, Balance, Principal Amount   $ 458      
Investment Owned, at Cost   324      
Investment Owned, at Fair Value   $ 342      
Fair Value As A Percentage of Member's Equity   1.00%      
Investment, Identifier [Axis]: Solar Holdings Bidco Limited, First Lien Secured Delayed Draw Loan SOFR          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SolarHoldingsBidcoLimitedMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   0.50%   0.50%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.85%   11.85%  
Investment, Acquisition Date   Mar. 23, 2023      
Investment Maturity Date   Sep. 28, 2029   Sep. 28, 2029  
Investment Owned, Balance, Principal Amount   $ 368      
Investment Owned, at Cost   360      
Investment Owned, at Fair Value   $ 366      
Fair Value As A Percentage of Member's Equity   1.10%      
Investment, Identifier [Axis]: Solar Holdings Bidco Limited, First Lien Secured Delayed Draw Loan SONIA          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SolarHoldingsBidcoLimitedMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Research & Consulting Services   Research & Consulting Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Sterling Overnight Index Average [Member]   Sterling Overnight Index Average [Member]  
Investment, Interest Rate, Floor   0.00%   0.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.71%   11.71%  
Investment, Acquisition Date   Mar. 23, 2023      
Investment Maturity Date   Sep. 28, 2029   Sep. 28, 2029  
Investment Owned, Balance, Principal Amount   $ 723      
Investment Owned, at Cost   882      
Investment Owned, at Fair Value   $ 984      
Fair Value As A Percentage of Member's Equity   2.80%      
Investment, Identifier [Axis]: Source Code Holdings, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SourceCodeHoldingsLLCMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Technology Hardware, Storage & Peripherals   Technology Hardware, Storage & Peripherals  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.96%   11.96%  
Investment, Acquisition Date   Aug. 10, 2021      
Investment Maturity Date   Jul. 30, 2027   Jul. 30, 2027  
Investment Owned, Balance, Principal Amount   $ 4,088      
Investment Owned, at Cost   4,039      
Investment Owned, at Fair Value   $ 4,047      
Fair Value As A Percentage of Member's Equity   11.70%      
Investment, Identifier [Axis]: Source Code Holdings, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SourceCodeHoldingsLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Technology Hardware, Storage & Peripherals   Technology Hardware, Storage & Peripherals  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.96%   11.96%  
Investment, Acquisition Date   Aug. 10, 2021      
Investment Maturity Date   Jul. 30, 2027   Jul. 30, 2027  
Investment Owned, Balance, Principal Amount   $ 14,952      
Investment Owned, at Cost   14,772      
Investment Owned, at Fair Value   $ 14,806      
Fair Value As A Percentage of Member's Equity   42.70%      
Investment, Identifier [Axis]: Source Code Holdings, LLC., First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SourceCodeHoldingsLLCMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Technology Hardware, Storage & Peripherals   Technology Hardware, Storage & Peripherals    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.50%   6.50%    
Investment Interest Rate 10.96%   10.96%    
Investment, Acquisition Date Aug. 10, 2021        
Investment Maturity Date Jul. 30, 2027   Jul. 30, 2027    
Investment Owned, Balance, Principal Amount $ 3,872        
Investment Owned, at Cost 3,839        
Investment Owned, at Fair Value $ 3,854        
Fair Value As A Percentage of Member's Equity 11.10%        
Investment, Identifier [Axis]: Source Code Holdings, LLC., First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SourceCodeHoldingsLLCMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Technology Hardware, Storage & Peripherals   Technology Hardware, Storage & Peripherals    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.50%   6.50%    
Investment Interest Rate 10.96%   10.96%    
Investment, Acquisition Date Aug. 10, 2021        
Investment Maturity Date Jul. 30, 2027   Jul. 30, 2027    
Investment Owned, Balance, Principal Amount $ 14,162        
Investment Owned, at Cost 14,041        
Investment Owned, at Fair Value $ 14,095        
Fair Value As A Percentage of Member's Equity 40.70%        
Investment, Identifier [Axis]: Sterling Pure Blocker, LLC (d/b/a Banner Industries, Inc.) Class B Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:SterlingPureBlockerLlcMember whfcl:SterlingPureBlockerLlcMember      
Investment, Type [Extensible Enumeration] whfcl:ClassBUnitsMember whfcl:ClassBUnitsMember whfcl:ClassBUnitsMember whfcl:ClassBUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering Construction & Engineering Construction & Engineering Construction & Engineering  
Investment, Acquisition Date Dec. 01, 2023 Dec. 01, 2023      
Investment Owned, Balance, Shares | shares 404 404 404 404  
Investment Owned, at Cost $ 404 $ 404      
Investment Owned, at Fair Value $ 388 $ 404      
Percent of net assets 0.10% 0.10% 0.10% 0.10%  
Investment, Identifier [Axis]: StoicLane MidCo, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:StoiclaneMidcoLlcMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Real Estate Services   Real Estate Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.50%   7.50%  
Investment Interest Rate   13.00%   13.00%  
Investment, Acquisition Date   Nov. 04, 2022      
Investment Maturity Date   Nov. 04, 2027   Nov. 04, 2027  
Investment Owned, Balance, Principal Amount   $ 5,545      
Investment Owned, at Cost   5,466      
Investment Owned, at Fair Value   $ 5,633      
Percent of net assets   1.80%   1.80%  
Investment, Identifier [Axis]: StoicLane MidCo, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:StoiclaneMidcoLlcMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Real Estate Services   Real Estate Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.50%   7.50%  
Investment Interest Rate   13.00%   13.00%  
Investment, Acquisition Date   Nov. 04, 2022      
Investment Maturity Date   Nov. 04, 2027   Nov. 04, 2027  
Investment Owned, Balance, Principal Amount   $ 4,606      
Investment Owned, at Cost   4,518      
Investment Owned, at Fair Value   $ 4,606      
Percent of net assets   1.50%   1.50%  
Investment, Identifier [Axis]: Sunless, Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SunlessInc.Member      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Personal Products   Personal Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.75%   6.75%  
Investment Interest Rate   12.21%   12.21%  
Investment, Acquisition Date   Oct. 21, 2019      
Investment Maturity Date   Aug. 13, 2025   Aug. 13, 2025  
Investment Owned, Balance, Principal Amount   $ 488      
Investment Owned, at Cost   485      
Investment Owned, at Fair Value   $ 484      
Fair Value As A Percentage of Member's Equity   1.40%      
Investment, Identifier [Axis]: Sunless, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:SunlessInc.Member      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Personal Products   Personal Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.75%   6.75%  
Investment Interest Rate   12.20%   12.20%  
Investment, Acquisition Date   Oct. 21, 2019      
Investment Maturity Date   Aug. 13, 2025   Aug. 13, 2025  
Investment Owned, Balance, Principal Amount   $ 5,507      
Investment Owned, at Cost   5,459      
Investment Owned, at Fair Value   $ 5,473      
Fair Value As A Percentage of Member's Equity   15.80%      
Investment, Identifier [Axis]: Surge Amuze Holdings Inc. First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Surge Amuze Holdings Inc [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Leisure Products   Leisure Products    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 10.46%   10.46%    
Investment, Acquisition Date Sep. 06, 2024        
Investment Maturity Date Sep. 06, 2029   Sep. 06, 2029    
Investment Owned, Balance, Principal Amount $ 584        
Investment Owned, at Cost 573        
Investment Owned, at Fair Value $ 577        
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: Surge Amuze Holdings Inc. First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Surge Amuze Holdings Inc [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Leisure Products   Leisure Products    
Investment, Variable Interest Rate, Type [Extensible Enumeration] us-gaap:PrimeRateMember   us-gaap:PrimeRateMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.00%   5.00%    
Investment Interest Rate 12.50%   12.50%    
Investment, Acquisition Date Sep. 06, 2024        
Investment Maturity Date Sep. 06, 2029   Sep. 06, 2029    
Investment Owned, Balance, Principal Amount $ 585        
Investment Owned, at Cost 574        
Investment Owned, at Fair Value $ 576        
Percent of net assets 0.20%   0.20%    
Investment, Identifier [Axis]: Surge Amuze Holdings Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Surge Amuze Holdings Inc [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Leisure Products   Leisure Products    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.00%   6.00%    
Investment Interest Rate 10.44%   10.44%    
Investment, Acquisition Date Sep. 06, 2024        
Investment Maturity Date Sep. 06, 2029   Sep. 06, 2029    
Investment Owned, Balance, Principal Amount $ 5,737        
Investment Owned, at Cost 5,629        
Investment Owned, at Fair Value $ 5,643        
Percent of net assets 2.00%   2.00%    
Investment, Identifier [Axis]: TOT Group, Inc. (d/b/a Netevia Group LLC) First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Tot Group, Inc. [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Transaction & Payment Processing Services [Member]   Transaction & Payment Processing Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 7.50%   7.50%    
Investment Interest Rate 11.83%   11.83%    
Investment, Acquisition Date Jun. 28, 2024        
Investment Maturity Date Jun. 28, 2029   Jun. 28, 2029    
Investment Owned, at Fair Value $ (1)        
Investment, Identifier [Axis]: TOT Group, Inc. (d/b/a Netevia Group LLC) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Tot Group, Inc. [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Transaction & Payment Processing Services [Member]   Transaction & Payment Processing Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 7.50%   7.50%    
Investment Interest Rate 11.83%   11.83%    
Investment, Acquisition Date Jun. 28, 2024        
Investment Maturity Date Jun. 28, 2029   Jun. 28, 2029    
Investment, Identifier [Axis]: TOT Group, Inc. (d/b/a Netevia Group LLC) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Tot Group, Inc. [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Transaction & Payment Processing Services [Member]   Transaction & Payment Processing Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 7.50%   7.50%    
Investment Interest Rate 11.83%   11.83%    
Investment, Acquisition Date Jun. 28, 2024        
Investment Maturity Date Jun. 28, 2029   Jun. 28, 2029    
Investment Owned, Balance, Principal Amount $ 8,239        
Investment Owned, at Cost 8,074        
Investment Owned, at Fair Value $ 8,067        
Percent of net assets 2.80%   2.80%    
Investment, Identifier [Axis]: TOUR Intermediate Holdings, LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:TOURIntermediateHoldingsLLCMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Investment Banking & Brokerage   Investment Banking & Brokerage  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.96%   11.96%  
Investment, Acquisition Date   May 19, 2020      
Investment Maturity Date   May 15, 2025   May 15, 2025  
Investment Owned, Balance, Principal Amount   $ 2,320      
Investment Owned, at Cost   2,315      
Investment Owned, at Fair Value   $ 2,320      
Fair Value As A Percentage of Member's Equity   6.70%      
Investment, Identifier [Axis]: TOUR Intermediate Holdings, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:TOURIntermediateHoldingsLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Investment Banking & Brokerage   Investment Banking & Brokerage  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   6.50%   6.50%  
Investment Interest Rate   11.96%   11.96%  
Investment, Acquisition Date   May 19, 2020      
Investment Maturity Date   May 15, 2025   May 15, 2025  
Investment Owned, Balance, Principal Amount   $ 2,657      
Investment Owned, at Cost   2,643      
Investment Owned, at Fair Value   $ 2,657      
Fair Value As A Percentage of Member's Equity   7.70%      
Investment, Identifier [Axis]: TableTrust Brands LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TabletrustBrandsLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services   IT Consulting And Other Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.75%   5.75%    
Investment Interest Rate 10.22%   10.22%    
Investment, Acquisition Date Dec. 24, 2024        
Investment Maturity Date Jun. 28, 2028   Jun. 28, 2028    
Investment Owned, Balance, Principal Amount $ 2,505        
Investment Owned, at Cost 2,468        
Investment Owned, at Fair Value $ 2,468        
Fair Value As A Percentage of Member's Equity 7.10%        
Investment, Identifier [Axis]: Team Car Care Holdings, First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:TeamCarCareHoldingsLLCMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Automotive Retail [Member]   Automotive Retail [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   Base Rate [Member]   Base Rate [Member]  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.48%   7.48%  
Investment Interest Rate   13.09%   13.09%  
Investment, Acquisition Date   Feb. 16, 2018      
Investment Maturity Date   Dec. 31, 2024   Dec. 31, 2024  
Investment Owned, Balance, Principal Amount   $ 12,407      
Investment Owned, at Cost   12,391      
Investment Owned, at Fair Value   $ 12,407      
Percent of net assets   3.90%   3.90%  
Investment, Identifier [Axis]: Telestream Holdings Corporation First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Telestream Holdings Corporation [Member] Telestream Holdings Corporation [Member]      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Technology Hardware, Storage & Peripherals Technology Hardware, Storage & Peripherals Technology Hardware, Storage & Peripherals Technology Hardware, Storage & Peripherals  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 9.75% 11.75% 9.75% 11.75%  
Investment Interest Rate   17.21%   17.21%  
Investment, Acquisition Date Oct. 15, 2020 Oct. 15, 2020      
Investment Maturity Date Oct. 15, 2025 Oct. 15, 2025 Oct. 15, 2025 Oct. 15, 2025  
Investment Owned, Balance, Principal Amount $ 1,116 $ 1,242      
Investment Owned, at Cost 1,051 1,228      
Investment Owned, at Fair Value $ 1,009 $ 1,223      
Investment, Interest Rate, Paid in Kind 14.21%   14.21%    
Percent of net assets 0.40% 0.40% 0.40% 0.40%  
Investment, Identifier [Axis]: Telestream Holdings Corporation First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Telestream Holdings Corporation [Member] Telestream Holdings Corporation [Member]      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Technology Hardware, Storage & Peripherals Technology Hardware, Storage & Peripherals Technology Hardware, Storage & Peripherals Technology Hardware, Storage & Peripherals  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 9.75% 11.75% 9.75% 11.75%  
Investment Interest Rate   17.28%   17.28%  
Investment, Acquisition Date Oct. 15, 2020 Oct. 15, 2020      
Investment Maturity Date Oct. 15, 2025 Oct. 15, 2025 Oct. 15, 2025 Oct. 15, 2025  
Investment Owned, Balance, Principal Amount $ 18,547 $ 15,763      
Investment Owned, at Cost 17,496 15,580      
Investment Owned, at Fair Value $ 17,063 $ 15,522      
Investment, Interest Rate, Paid in Kind 14.21%   14.21%    
Percent of net assets 5.90% 4.90% 5.90% 4.90%  
Investment, Identifier [Axis]: The Kyjen Company, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TheKyjenCompanyLLCMember whfcl:TheKyjenCompanyLLCMember      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Household Products [Member] Household Products [Member] Household Products [Member] Household Products [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 7.50% 6.50% 7.50%  
Investment Interest Rate 10.97% 13.21% 10.97% 13.21%  
Investment, Acquisition Date Apr. 05, 2021 Apr. 05, 2021      
Investment Maturity Date Apr. 05, 2026 Apr. 05, 2026 Apr. 05, 2026 Apr. 05, 2026  
Investment Owned, Balance, Principal Amount $ 798        
Investment Owned, at Cost 795        
Investment Owned, at Fair Value $ 761 $ (31)      
Investment, Interest Rate, Paid in Kind 0.75% 1.00% 0.75% 1.00%  
Investment, Interest Rate, Paid in Cash 10.22% 12.21% 10.22% 12.21%  
Percent of net assets 0.30%   0.30%    
Investment, Identifier [Axis]: The Kyjen Company, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TheKyjenCompanyLLCMember whfcl:TheKyjenCompanyLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Household Products [Member] Household Products [Member] Household Products [Member] Household Products [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.25% 7.50% 7.25% 7.50%  
Investment Interest Rate 12.05% 13.21% 12.05% 13.21%  
Investment, Acquisition Date Apr. 05, 2021 Apr. 05, 2021      
Investment Maturity Date Apr. 05, 2026 Apr. 05, 2026 Apr. 05, 2026 Apr. 05, 2026  
Investment Owned, Balance, Principal Amount $ 11,350 $ 11,358      
Investment Owned, at Cost 11,309 11,282      
Investment Owned, at Fair Value $ 10,895 $ 10,904      
Investment, Interest Rate, Paid in Kind 0.75% 1.00% 0.75% 1.00%  
Investment, Interest Rate, Paid in Cash 11.30% 12.21% 11.30% 12.21%  
Percent of net assets 3.80% 3.40% 3.80% 3.40%  
Investment, Identifier [Axis]: Token Buyer, Inc First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TokenBuyerIncMember whfcl:TokenBuyerIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Household Appliances Household Appliances Household Appliances Household Appliances  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 0.50% 0.50% 0.50% 0.50%  
Spread Above Index 6.00% 6.00% 6.00% 6.00%  
Investment Interest Rate 10.74% 11.53% 10.74% 11.53%  
Investment, Acquisition Date May 26, 2022 May 26, 2022      
Investment Maturity Date May 31, 2029 May 31, 2029 May 31, 2029 May 31, 2029  
Investment Owned, Balance, Principal Amount $ 7,070 $ 7,142      
Investment Owned, at Cost 6,709 6,695      
Investment Owned, at Fair Value $ 5,658 $ 5,966      
Percent of net assets 2.00% 1.90% 2.00% 1.90%  
Investment, Identifier [Axis]: Trailhead Media LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Trailhead Media L L C [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Advertising   Advertising    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.82%   9.82%    
Investment, Acquisition Date Dec. 30, 2024        
Investment Maturity Date Dec. 28, 2029   Dec. 28, 2029    
Investment, Interest Rate, Paid in Kind 0.75%   0.75%    
Investment, Interest Rate, Paid in Cash 9.07%   9.07%    
Investment, Identifier [Axis]: Trailhead Media LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Trailhead Media L L C [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Advertising   Advertising    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.82%   9.82%    
Investment, Acquisition Date Dec. 30, 2024        
Investment Maturity Date Dec. 28, 2029   Dec. 28, 2029    
Investment, Interest Rate, Paid in Kind 0.75%   0.75%    
Investment, Interest Rate, Paid in Cash 9.07%   9.07%    
Investment, Identifier [Axis]: Trailhead Media LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] Trailhead Media L L C [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Advertising   Advertising    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.82%   9.82%    
Investment, Acquisition Date Dec. 30, 2024        
Investment Maturity Date Dec. 28, 2029   Dec. 28, 2029    
Investment Owned, Balance, Principal Amount $ 6,648        
Investment Owned, at Cost 6,548        
Investment Owned, at Fair Value $ 6,548        
Investment, Interest Rate, Paid in Kind 0.75%   0.75%    
Investment, Interest Rate, Paid in Cash 9.07%   9.07%    
Percent of net assets 2.30%   2.30%    
Investment, Identifier [Axis]: Transervice Holdings, Inc. (d/b/a Transervice Logistics, Inc.) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TranserviceHoldingsIncMember whfcl:TranserviceHoldingsIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics Air Freight & Logistics  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 2.00% 2.00% 2.00% 2.00%  
Spread Above Index 7.25% 7.50% 7.25% 7.50%  
Investment Interest Rate 11.71% 12.96% 11.71% 12.96%  
Investment, Acquisition Date Jun. 29, 2023 Jun. 29, 2023      
Investment Maturity Date Jun. 29, 2028 Jun. 29, 2028 Jun. 29, 2028 Jun. 29, 2028  
Investment Owned, Balance, Principal Amount $ 8,663 $ 8,888      
Investment Owned, at Cost 8,481 8,648      
Investment Owned, at Fair Value $ 8,715 $ 8,743      
Percent of net assets 3.00% 2.80% 3.00% 2.80%  
Investment, Identifier [Axis]: Trimlite Buyer LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TrimliteBuyerLLCMember whfcl:TrimliteBuyerLLCMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] country:CA country:CA country:CA country:CA  
Investment, Industry Sector [Extensible Enumeration] Building Products Building Products Building Products Building Products  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:CanadianDollarOfferedRateMember whfcl:CanadianDollarOfferedRateMember whfcl:CanadianDollarOfferedRateMember whfcl:CanadianDollarOfferedRateMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 9.99% 11.94% 9.99% 11.94%  
Investment, Acquisition Date Jul. 27, 2021 Jul. 27, 2021      
Investment Maturity Date Jul. 27, 2027 Jul. 27, 2027 Jul. 27, 2027 Jul. 27, 2027  
Investment Owned, Balance, Principal Amount     $ 18,984 $ 19,624  
Investment Owned, at Cost $ 15,006 $ 15,472      
Investment Owned, at Fair Value $ 13,206 $ 14,810      
Percent of net assets 4.60% 4.70% 4.60% 4.70%  
Investment, Identifier [Axis]: TriplePoint Acquisition Holdings LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TriplepointAcquisitionHoldingsLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering   Construction & Engineering    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.83%   9.83%    
Investment, Acquisition Date Jun. 14, 2024        
Investment Maturity Date May 31, 2029   May 31, 2029    
Investment Owned, at Fair Value $ 9        
Investment, Identifier [Axis]: TriplePoint Acquisition Holdings LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TriplepointAcquisitionHoldingsLlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering   Construction & Engineering    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.83%   9.83%    
Investment, Acquisition Date Jun. 14, 2024        
Investment Maturity Date May 31, 2029   May 31, 2029    
Investment Owned, at Fair Value $ 12        
Investment, Identifier [Axis]: TriplePoint Acquisition Holdings LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TriplepointAcquisitionHoldingsLlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Construction & Engineering   Construction & Engineering    
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]   Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 5.50%   5.50%    
Investment Interest Rate 9.83%   9.83%    
Investment, Acquisition Date Jun. 14, 2024        
Investment Maturity Date May 31, 2029   May 31, 2029    
Investment Owned, Balance, Principal Amount $ 5,349        
Investment Owned, at Cost 5,254        
Investment Owned, at Fair Value $ 5,338        
Fair Value As A Percentage of Member's Equity 15.40%        
Investment, Identifier [Axis]: Turnberry Solutions., First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TurnberrySolutionsInc.Member whfcl:TurnberrySolutionsInc.Member      
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember whfcl:FirstLienSecuredRevolvingLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.75% 5.75% 5.75% 5.75%  
Investment Interest Rate 10.21% 11.45% 10.21% 11.45%  
Investment, Acquisition Date Aug. 10, 2021 Aug. 10, 2021      
Investment Maturity Date Sep. 02, 2026 Sep. 02, 2026 Sep. 02, 2026 Sep. 02, 2026  
Investment Owned, at Fair Value $ 4 $ 2      
Investment, Identifier [Axis]: Turnberry Solutions., First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TurnberrySolutionsInc.Member whfcl:TurnberrySolutionsInc.Member      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Variable Interest Rate, Type [Extensible Enumeration] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 5.75% 5.75% 5.75% 5.75%  
Investment Interest Rate 10.21% 11.45% 10.21% 11.45%  
Investment, Acquisition Date Aug. 10, 2021 Aug. 10, 2021      
Investment Maturity Date Sep. 02, 2026 Sep. 02, 2026 Sep. 02, 2026 Sep. 02, 2026  
Investment Owned, Balance, Principal Amount $ 5,964 $ 6,026      
Investment Owned, at Cost 5,924 5,962      
Investment Owned, at Fair Value $ 5,964 $ 5,979      
Fair Value As A Percentage of Member's Equity 17.20% 17.20%      
Investment, Identifier [Axis]: Twin Ridge CRS, LP (d/b/a CRS OneSource) Class A Common Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:TwinRidgeCrsLpMember        
Investment, Type [Extensible Enumeration] whfcl:ClassCommonUnitsMember   whfcl:ClassCommonUnitsMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Food Distributors   Food Distributors    
Investment, Acquisition Date May 10, 2024        
Investment Owned, Balance, Shares | shares 63   63    
Investment Owned, at Cost $ 317        
Investment Owned, at Fair Value $ 350        
Percent of net assets 0.10%   0.10%    
Investment, Identifier [Axis]: US Methanol Midco LLC (d/b/a US Methanol LLC) First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:UsMethanolMidcoLlcMember      
Investment, Type [Extensible Enumeration]   whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Commodity Chemicals [Member]   Commodity Chemicals [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.75%   7.75%  
Investment Interest Rate   13.29%   13.29%  
Investment, Acquisition Date   Dec. 20, 2022      
Investment Maturity Date   Dec. 20, 2027   Dec. 20, 2027  
Investment Owned, Balance, Principal Amount   $ 9,540      
Investment Owned, at Cost   9,345      
Investment Owned, at Fair Value   $ 9,449      
Percent of net assets   3.00%   3.00%  
Investment, Identifier [Axis]: US Methanol Midco LLC (d/b/a US Methanol LLC) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration]   whfcl:UsMethanolMidcoLlcMember      
Investment, Type [Extensible Enumeration]   First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration]   Commodity Chemicals [Member]   Commodity Chemicals [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration]   whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor   1.00%   1.00%  
Spread Above Index   7.75%   7.75%  
Investment Interest Rate   13.28%   13.28%  
Investment, Acquisition Date   Dec. 20, 2022      
Investment Maturity Date   Dec. 20, 2027   Dec. 20, 2027  
Investment Owned, Balance, Principal Amount   $ 5,203      
Investment Owned, at Cost   5,111      
Investment Owned, at Fair Value   $ 5,153      
Percent of net assets   1.60%   1.60%  
Investment, Identifier [Axis]: UserZoom Technologies, Inc. First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:UserzoomTechnologiesIncMember whfcl:UserzoomTechnologiesIncMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Application Software Application Software Application Software Application Software  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 7.50% 7.50% 7.50% 7.50%  
Investment Interest Rate 12.75% 12.99% 12.75% 12.99%  
Investment, Acquisition Date Jan. 12, 2023 Jan. 12, 2023      
Investment Maturity Date Apr. 05, 2029 Apr. 05, 2029 Apr. 05, 2029 Apr. 05, 2029  
Investment Owned, Balance, Principal Amount $ 9,819 $ 9,819      
Investment Owned, at Cost 9,618 9,570      
Investment Owned, at Fair Value $ 9,809 $ 9,719      
Percent of net assets 3.40% 3.20% 3.40% 3.20%  
Investment, Identifier [Axis]: Vistria Blocked MGT Investor, LP (d/b/a MGT Consulting Group) Series A Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:VistriaBlockedMgtInvestorLpMember whfcl:VistriaBlockedMgtInvestorLpMember      
Investment, Type [Extensible Enumeration] whfcl:SeriesUnitsMember whfcl:ClassAUnitsMember whfcl:SeriesUnitsMember whfcl:ClassAUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services IT Consulting And Other Services  
Investment, Acquisition Date Apr. 10, 2023 Apr. 10, 2023      
Investment Owned, at Cost $ 314 $ 314      
Investment Owned, at Fair Value $ 493 $ 406      
Percent of net assets 0.20% 0.10% 0.20% 0.10%  
Investment, Identifier [Axis]: W Electric Intermediate Holdings, LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] W Electric Intermediate Holdings, LLC [Member]        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Industrial Machinery & Supplies & Components   Industrial Machinery & Supplies & Components    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.50%   6.50%    
Investment Interest Rate 10.86%   10.86%    
Investment, Acquisition Date Aug. 15, 2024        
Investment Maturity Date Aug. 15, 2029   Aug. 15, 2029    
Investment Owned, at Fair Value $ 9        
Investment, Interest Rate, Paid in Kind 1.00%   1.00%    
Investment, Interest Rate, Paid in Cash 9.86%   9.86%    
Investment, Identifier [Axis]: W Electric Intermediate Holdings, LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] W Electric Intermediate Holdings, LLC [Member]        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Industrial Machinery & Supplies & Components   Industrial Machinery & Supplies & Components    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.50%   6.50%    
Investment Interest Rate 10.86%   10.86%    
Investment, Acquisition Date Aug. 15, 2024        
Investment Maturity Date Aug. 15, 2029   Aug. 15, 2029    
Investment Owned, Balance, Principal Amount $ 12,322        
Investment Owned, at Cost 12,124        
Investment Owned, at Fair Value $ 12,216        
Investment, Interest Rate, Paid in Kind 1.00%   1.00%    
Investment, Interest Rate, Paid in Cash 9.86%   9.86%    
Percent of net assets 4.30%   4.30%    
Investment, Identifier [Axis]: WHF STRS Ohio Senior Loan Fund LLC Equity          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:WHFSTRSOhioSeniorLoanFundLLCMember whfcl:WHFSTRSOhioSeniorLoanFundLLCMember      
Investment, Type [Extensible Enumeration] Equity Investments Equity Investments Equity Investments Equity Investments  
Investment Owned, at Fair Value $ 22,741 $ 22,782     20,160
Investment, Identifier [Axis]: WHF STRS Ohio Senior Loan Fund LLC Interests          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:WHFSTRSOhioSeniorLoanFundMember whfcl:WHFSTRSOhioSeniorLoanFundMember      
Investment, Type [Extensible Enumeration] whfcl:LLCInterestsMember whfcl:LLCInterestsMember whfcl:LLCInterestsMember whfcl:LLCInterestsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Specialized Finance [Member] Specialized Finance [Member] Specialized Finance [Member] Specialized Finance [Member]  
Investment, Acquisition Date Jul. 19, 2019 Jul. 19, 2019      
Investment Owned, Balance, Shares | shares 21,104 21,104 21,104 21,104  
Investment Owned, at Cost $ 21,104 $ 21,104      
Investment Owned, at Fair Value $ 22,741 $ 22,782      
Percent of net assets 7.90% 7.20% 7.90% 7.20%  
Investment, Identifier [Axis]: WHF STRS Ohio Senior Loan Fund LLC Subordinated Note          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:WHFSTRSOhioSeniorLoanFundLLCMember whfcl:WHFSTRSOhioSeniorLoanFundLLCMember      
Investment, Type [Extensible Enumeration] Subordinated Debt [Member] Subordinated Debt [Member] Subordinated Debt [Member] Subordinated Debt [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Specialized Finance [Member] Specialized Finance [Member] Specialized Finance [Member] Specialized Finance [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Spread Above Index 6.50% 6.50% 6.50% 6.50%  
Investment Interest Rate 10.83% 11.85% 10.83% 11.85%  
Investment, Acquisition Date Jul. 19, 2019 Jul. 19, 2019      
Investment Owned, Balance, Principal Amount $ 84,416 $ 84,416      
Investment Owned, at Cost 84,416 84,416      
Investment Owned, at Fair Value $ 84,416 $ 84,416     $ 80,000
Percent of net assets 29.50% 26.60% 29.50% 26.60%  
Investment, Identifier [Axis]: Wamp;A Intermediate Co., LLC First Lien Secured Delayed Draw Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:WakefieldAndAssociatesIntermediateCo.LlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredDelayedDrawLoanMember   whfcl:FirstLienSecuredDelayedDrawLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Health Care Services   Health Care Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.25%   6.25%    
Investment Interest Rate 10.58%   10.58%    
Investment, Acquisition Date Aug. 01, 2024        
Investment Maturity Date Aug. 01, 2029   Aug. 01, 2029    
Investment Owned, at Fair Value $ 2        
Investment, Identifier [Axis]: Wamp;A Intermediate Co., LLC First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:WakefieldAndAssociatesIntermediateCo.LlcMember        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Health Care Services   Health Care Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.25%   6.25%    
Investment Interest Rate 10.58%   10.58%    
Investment, Acquisition Date Aug. 01, 2024        
Investment Maturity Date Aug. 01, 2029   Aug. 01, 2029    
Investment Owned, Balance, Principal Amount $ 258        
Investment Owned, at Cost 253        
Investment Owned, at Fair Value $ 254        
Percent of net assets 0.10%   0.10%    
Investment, Identifier [Axis]: Wamp;A Intermediate Co., LLC First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:WakefieldAndAssociatesIntermediateCo.LlcMember        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Health Care Services   Health Care Services    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.25%   6.25%    
Investment Interest Rate 10.58%   10.58%    
Investment, Acquisition Date Aug. 01, 2024        
Investment Maturity Date Aug. 01, 2029   Aug. 01, 2029    
Investment Owned, Balance, Principal Amount $ 7,689        
Investment Owned, at Cost 7,548        
Investment Owned, at Fair Value $ 7,555        
Percent of net assets 2.60%   2.60%    
Investment, Identifier [Axis]: What If Media Group, LLC Common Units          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:WhatIfMediaGroupLLCMember whfcl:WhatIfMediaGroupLLCMember      
Investment, Type [Extensible Enumeration] whfcl:CommonUnitsMember whfcl:CommonUnitsMember whfcl:CommonUnitsMember whfcl:CommonUnitsMember  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Interactive Media And Services [Member] Interactive Media And Services [Member] Interactive Media And Services [Member] Interactive Media And Services [Member]  
Investment, Acquisition Date Jul. 02, 2021 Jul. 02, 2021      
Investment Owned, Balance, Shares | shares 3,081 3,081 3,081 3,081  
Investment Owned, at Cost $ 851 $ 851      
Investment Owned, at Fair Value $ 1,756 $ 1,615      
Percent of net assets 0.60% 0.50% 0.60% 0.50%  
Investment, Identifier [Axis]: Whitestone Home Furnishings, LLC (d/b/a Saatva, Inc.) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:WhitestoneHomeFurnishingsLlcMember whfcl:WhitestoneHomeFurnishingsLlcMember      
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member] First Lien Secured Term Loan [Member]  
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment, Industry Sector [Extensible Enumeration] Home Furnishings [Member] Home Furnishings [Member] Home Furnishings [Member] Home Furnishings [Member]  
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember whfcl:SecuredOvernightFinancingRateSofrMember  
Investment, Interest Rate, Floor 1.00% 1.00% 1.00% 1.00%  
Spread Above Index 6.00% 6.50% 6.00% 6.50%  
Investment Interest Rate 10.46% 11.96% 10.46% 11.96%  
Investment, Acquisition Date Nov. 06, 2023 Nov. 06, 2023      
Investment Maturity Date Aug. 20, 2026 Aug. 20, 2026 Aug. 20, 2026 Aug. 20, 2026  
Investment Owned, Balance, Principal Amount $ 2,930 $ 2,990      
Investment Owned, at Cost 2,887 2,919      
Investment Owned, at Fair Value $ 2,930 $ 2,919      
Percent of net assets 1.00% 0.90% 1.00% 0.90%  
Investment, Identifier [Axis]: Zephyr Buyer, L.P. (d/b/a The Weather Company, LLC) First Lien Secured Revolving Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ZephyrBuyerL.p.Member        
Investment, Type [Extensible Enumeration] whfcl:FirstLienSecuredRevolvingLoanMember   whfcl:FirstLienSecuredRevolvingLoanMember    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Interactive Media And Services [Member]   Interactive Media And Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.50%   6.50%    
Investment Interest Rate 10.83%   10.83%    
Investment, Acquisition Date Jan. 31, 2024        
Investment Maturity Date Jan. 31, 2030   Jan. 31, 2030    
Investment Owned, at Fair Value $ 48        
Investment, Identifier [Axis]: Zephyr Buyer, L.P. (d/b/a The Weather Company, LLC) First Lien Secured Term Loan          
Schedule of Investments [Line Items]          
Investment, Issuer Name [Extensible Enumeration] whfcl:ZephyrBuyerL.p.Member        
Investment, Type [Extensible Enumeration] First Lien Secured Term Loan [Member]   First Lien Secured Term Loan [Member]    
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment, Industry Sector [Extensible Enumeration] Interactive Media And Services [Member]   Interactive Media And Services [Member]    
Investment, Variable Interest Rate, Type [Extensible Enumeration] whfcl:SecuredOvernightFinancingRateSofrMember   whfcl:SecuredOvernightFinancingRateSofrMember    
Investment, Interest Rate, Floor 1.00%   1.00%    
Spread Above Index 6.50%   6.50%    
Investment Interest Rate 10.83%   10.83%    
Investment, Acquisition Date Jan. 31, 2024        
Investment Maturity Date Jan. 31, 2030   Jan. 31, 2030    
Investment Owned, Balance, Principal Amount $ 14,087        
Investment Owned, at Cost 13,789        
Investment Owned, at Fair Value $ 14,166        
Percent of net assets 5.00%   5.00%    
Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember, country:CA srt:NorthAmericaMember, country:CA srt:NorthAmericaMember, country:CA srt:NorthAmericaMember, country:CA  
Investment Owned, at Cost $ 631,941 $ 693,621      
Investment Owned, at Fair Value $ 596,626 $ 656,707      
Percent of net assets 208.40% 207.40% 208.40% 207.40%  
Money Market Funds          
Schedule of Investments [Line Items]          
Money Market Funds amortized cost $ 13,249        
Money Market Fair Value $ 13,249        
Percent of net assets 4.60%   4.60%    
Money Market Funds | STRS JV          
Schedule of Investments [Line Items]          
Money Market Funds amortized cost $ 767        
Money Market Fair Value $ 767        
Percent of net assets 2.20%   2.20%    
Goldman Sachs Money Market Fund (CUSIP: 38141W315)          
Schedule of Investments [Line Items]          
Weighted average interest rate 4.33%   4.33%    
Money Market Funds amortized cost $ 837        
Money Market Fair Value $ 837        
Percent of net assets 0.30%   0.30%    
Goldman Sachs Money Market Fund (CUSIP: 38141W315) | STRS JV          
Schedule of Investments [Line Items]          
Weighted average interest rate 4.33%   4.33%    
Money Market Funds amortized cost $ 242        
Money Market Fair Value $ 242        
Percent of net assets 0.70%   0.70%    
Invesco Treasury Money Market Fund (CUSIP: X9USDINVE)          
Schedule of Investments [Line Items]          
Weighted average interest rate 3.83%   3.83%    
Money Market Funds amortized cost $ 12,412        
Money Market Fair Value $ 12,412        
Percent of net assets 4.30%   4.30%    
Invesco Treasury Money Market Fund (CUSIP: X9USDINVE) | STRS JV          
Schedule of Investments [Line Items]          
Weighted average interest rate 4.39%   4.39%    
Money Market Funds amortized cost $ 525        
Money Market Fair Value $ 525        
Percent of net assets 1.50%   1.50%    
Advertising          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 11,937 $ 12,009      
Investment Owned, at Fair Value $ 12,035 $ 12,040      
Fair Value As A Percentage of Member's Equity 34.80% 34.70%      
Advertising | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment Owned, at Cost $ 16,365        
Investment Owned, at Fair Value $ 16,862        
Percent of net assets 6.00%   6.00%    
Air Freight & Logistics          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 3,286 $ 3,503      
Investment Owned, at Fair Value $ 3,311 $ 3,504      
Fair Value As A Percentage of Member's Equity 9.60% 10.10%      
Air Freight & Logistics | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 29,360 $ 23,689      
Investment Owned, at Fair Value $ 28,518 $ 22,616      
Percent of net assets 9.90% 7.20% 9.90% 7.20%  
Aerospace & Defense          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment Owned, at Cost $ 3,633        
Investment Owned, at Fair Value $ 3,682        
Fair Value As A Percentage of Member's Equity 10.60%        
Application Software | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 36,508 $ 39,567      
Investment Owned, at Fair Value $ 26,924 $ 34,202      
Percent of net assets 9.40% 11.00% 9.40% 11.00%  
Broadline Retail          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 18,577 $ 18,798      
Investment Owned, at Fair Value $ 17,827 $ 18,759      
Fair Value As A Percentage of Member's Equity 51.50% 54.10%      
Broadline Retail | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 4,556 $ 19,000      
Investment Owned, at Fair Value $ 4,580 $ 19,079      
Percent of net assets 1.60% 6.10% 1.60% 6.10%  
Building Products          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 13,445 $ 13,541      
Investment Owned, at Fair Value $ 13,437 $ 13,313      
Fair Value As A Percentage of Member's Equity 38.80% 38.40%      
Building Products | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] country:CA country:CA country:CA country:CA  
Investment Owned, at Cost $ 15,006 $ 15,472      
Investment Owned, at Fair Value $ 13,206 $ 14,810      
Percent of net assets 4.60% 4.70% 4.60% 4.70%  
Construction & Engineering          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 16,016 $ 9,476      
Investment Owned, at Fair Value $ 16,253 $ 9,550      
Fair Value As A Percentage of Member's Equity 47.00% 27.40%      
Construction & Engineering | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 3,539 $ 137      
Investment Owned, at Fair Value $ 3,539 $ 137      
Percent of net assets 1.20%   1.20%    
Data Processing & Outsourced Services          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 14,234 $ 14,969      
Investment Owned, at Fair Value $ 12,885 $ 14,659      
Fair Value As A Percentage of Member's Equity 37.20% 42.30%      
Data Processing & Outsourced Services | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 28,409 $ 34,137      
Investment Owned, at Fair Value $ 28,572 $ 33,997      
Percent of net assets 10.00% 10.80% 10.00% 10.80%  
Diversified Support Services          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 19,107 $ 19,246      
Investment Owned, at Fair Value $ 19,282 $ 19,136      
Fair Value As A Percentage of Member's Equity 55.70% 55.20%      
Diversified Support Services | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 9,559 $ 9,354      
Investment Owned, at Fair Value $ 9,414 $ 9,293      
Percent of net assets 3.30% 2.90% 3.30% 2.90%  
Electrical Components & Equipment          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment Owned, at Cost $ 3,479        
Investment Owned, at Fair Value $ 3,479        
Fair Value As A Percentage of Member's Equity 10.10%        
Electronic Equipment & Instruments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment Owned, at Cost   $ 13,203      
Investment Owned, at Fair Value   $ 13,269      
Fair Value As A Percentage of Member's Equity   38.30%      
Environmental & Facilities Services          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 29,529 $ 19,632      
Investment Owned, at Fair Value $ 29,963 $ 19,691      
Fair Value As A Percentage of Member's Equity 86.60% 56.90%      
Environmental & Facilities Services | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment Owned, at Cost   $ 22,984      
Investment Owned, at Fair Value   $ 22,895      
Percent of net assets   7.20%   7.20%  
Health Care Facilities          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment Owned, at Cost $ 7,944        
Investment Owned, at Fair Value $ 8,004        
Fair Value As A Percentage of Member's Equity 23.10%        
Health Care Facilities | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 8,694 $ 8,973      
Investment Owned, at Fair Value $ 8,660 $ 8,966      
Percent of net assets 3.00% 2.80% 3.00% 2.80%  
Health Care Services          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 4,898 $ 4,922      
Investment Owned, at Fair Value $ 4,995 $ 5,022      
Fair Value As A Percentage of Member's Equity 14.40% 14.50%      
Health Care Services | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 19,577 $ 17,577      
Investment Owned, at Fair Value $ 19,589 $ 17,643      
Percent of net assets 6.90% 5.50% 6.90% 5.50%  
Health Care Supplies          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 7,461 $ 7,500      
Investment Owned, at Fair Value $ 7,696 $ 7,530      
Fair Value As A Percentage of Member's Equity 22.20% 21.70%      
Health Care Supplies | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 20,142 $ 20,056      
Investment Owned, at Fair Value $ 19,535 $ 18,983      
Percent of net assets 6.80% 6.00% 6.80% 6.00%  
Household Appliances          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 7,649 $ 7,808      
Investment Owned, at Fair Value $ 7,632 $ 8,168      
Fair Value As A Percentage of Member's Equity 22.00% 23.60%      
Household Appliances | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 22,326 $ 22,088      
Investment Owned, at Fair Value $ 21,255 $ 21,397      
Percent of net assets 7.40% 6.80% 7.40% 6.80%  
Industrial Machinery & Supplies & Components          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment Owned, at Cost   $ 6,498      
Investment Owned, at Fair Value   $ 6,561      
Fair Value As A Percentage of Member's Equity   18.90%      
Industrial Machinery & Supplies & Components | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 12,124 $ 5,536      
Investment Owned, at Fair Value $ 12,225 $ 5,364      
Percent of net assets 4.30% 1.70% 4.30% 1.70%  
Investment Banking & Brokerage          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment Owned, at Cost   $ 4,958      
Investment Owned, at Fair Value   $ 4,977      
Fair Value As A Percentage of Member's Equity   14.40%      
Investment Banking & Brokerage | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment Owned, at Cost   $ 3,521      
Investment Owned, at Fair Value   $ 3,522      
Percent of net assets   1.10%   1.10%  
IT Consulting And Other Services          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 32,427 $ 50,974      
Investment Owned, at Fair Value $ 32,720 $ 51,295      
Fair Value As A Percentage of Member's Equity 94.60% 147.90%      
IT Consulting And Other Services | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment Owned, at Cost   $ 3,741      
Investment Owned, at Fair Value   $ 3,745      
Percent of net assets   1.20%   1.20%  
Leisure Products | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 45,674 $ 32,063      
Investment Owned, at Fair Value $ 23,298 $ 18,488      
Percent of net assets 8.10% 5.80% 8.10% 5.80%  
Packaged Foods & Meats          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 6,939 $ 6,904      
Investment Owned, at Fair Value $ 7,009 $ 6,904      
Fair Value As A Percentage of Member's Equity 20.20% 19.90%      
Packaged Foods & Meats | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment Owned, at Cost $ 4,024        
Investment Owned, at Fair Value $ 4,087        
Percent of net assets 1.40%   1.40%    
Paper & Plastic Packaging Products & Materials          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 14,964 $ 14,939      
Investment Owned, at Fair Value $ 14,881 $ 14,913      
Fair Value As A Percentage of Member's Equity 43.20% 43.10%      
Personal Products          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment Owned, at Cost   $ 5,944      
Investment Owned, at Fair Value   $ 5,957      
Fair Value As A Percentage of Member's Equity   17.20%      
Pharmaceuticals          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment Owned, at Cost $ 16,411 $ 16,523      
Investment Owned, at Fair Value $ 15,461 $ 16,416      
Fair Value As A Percentage of Member's Equity 44.70% 47.30%      
Real Estate Services          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment Owned, at Cost $ 14,554 $ 20,540      
Investment Owned, at Fair Value $ 13,782 $ 19,256      
Fair Value As A Percentage of Member's Equity 39.80% 55.60%      
Research & Consulting Services          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 11,900 $ 15,815      
Investment Owned, at Fair Value $ 11,977 $ 16,149      
Fair Value As A Percentage of Member's Equity 34.60% 46.50%      
Research & Consulting Services | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 4,823 $ 8,166      
Investment Owned, at Fair Value $ 4,927 $ 8,143      
Percent of net assets 1.70% 2.50% 1.70% 2.50%  
Systems Software | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 16,573 $ 20,618      
Investment Owned, at Fair Value $ 17,267 $ 11,523      
Percent of net assets 5.90% 3.60% 5.90% 3.60%  
Technology Hardware, Storage & Peripherals          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 17,880 $ 18,811      
Investment Owned, at Fair Value $ 17,949 $ 18,853      
Fair Value As A Percentage of Member's Equity 51.80% 54.40%      
Technology Hardware, Storage & Peripherals | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 18,547 $ 16,808      
Investment Owned, at Fair Value $ 18,072 $ 16,745      
Percent of net assets 6.30% 5.30% 6.30% 5.30%  
Distributors          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment Owned, at Cost $ 9,307        
Investment Owned, at Fair Value $ 9,372        
Fair Value As A Percentage of Member's Equity 27.10%        
Distributors | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 10,563 $ 15,946      
Investment Owned, at Fair Value $ 10,690 $ 12,475      
Percent of net assets 3.70% 3.90% 3.70% 3.90%  
Food Distributors          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember   srt:NorthAmericaMember    
Investment Owned, at Cost $ 4,919        
Investment Owned, at Fair Value $ 4,993        
Fair Value As A Percentage of Member's Equity 14.40%        
Wireless Telecommunication Services          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration] srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember srt:NorthAmericaMember  
Investment Owned, at Cost $ 6,256 $ 6,294      
Investment Owned, at Fair Value $ 6,332 $ 6,295      
Fair Value As A Percentage of Member's Equity 18.30% 18.20%      
Wireless Telecommunication Services | Debt Investments          
Schedule of Investments [Line Items]          
Investment, Issuer Geographic Region [Extensible Enumeration]   srt:NorthAmericaMember   srt:NorthAmericaMember  
Investment Owned, at Cost   $ 21,226      
Investment Owned, at Fair Value   $ 20,969      
Percent of net assets   6.60%   6.60%