v3.26.1
Fair Value of Financial Instruments - Schedule of Unobservable Inputs (Details)
$ in Thousands
Jun. 30, 2026
USD ($)
investment
Dec. 31, 2025
USD ($)
investment
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value $ 4,079,384 [1],[2],[3] $ 4,071,008 [4],[5],[6]
Number of investments | investment 1 1
Senior Secured First Lien Debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value $ 3,111,375 $ 3,136,374
Senior Secured Second Lien Debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 151,687 152,406
Subordinated Debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 276,251 259,132
Collateralized Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 3,898 4,861
Equity/Other    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 317,966 293,279
FBLC Senior Loan Fund, LLC    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 218,207 224,956
Level 3    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 4,000,024 3,998,057
Level 3 | Senior Secured First Lien Debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 3,105,812 3,121,003
Level 3 | Senior Secured First Lien Debt | Unobservable Inputs Not Developed    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 32,359 96,537
Level 3 | Senior Secured First Lien Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 2,861,199 2,970,031
Level 3 | Senior Secured First Lien Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 178,462 32,285
Level 3 | Senior Secured First Lien Debt | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 33,792 22,150
Level 3 | Senior Secured Second Lien Debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 97,785 110,594
Level 3 | Senior Secured Second Lien Debt | Unobservable Inputs Not Developed    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 4,095 16,600
Level 3 | Senior Secured Second Lien Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 54,897 55,631
Level 3 | Senior Secured Second Lien Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 38,793 37,695
Level 3 | Senior Secured Second Lien Debt | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value   668
Level 3 | Subordinated Debt    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 276,251 259,132
Level 3 | Subordinated Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 41,031 41,466
Level 3 | Subordinated Debt | Market Yield | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 58,990 33,911
Level 3 | Subordinated Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 10,130 9,654
Level 3 | Subordinated Debt | Tangible Net Asset Value Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 166,100 174,101
Level 3 | Collateralized Securities    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 3,898 4,861
Level 3 | Collateralized Securities | Discount Margin | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 3,431 4,322
Level 3 | Collateralized Securities | Asset Recovery | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 467  
Level 3 | Collateralized Securities | Asset Price | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value   539
Level 3 | Equity/Other    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 298,071 277,511
Level 3 | Equity/Other | Unobservable Inputs Not Developed    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 332 0
Level 3 | Equity/Other | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 20,874 20,310
Level 3 | Equity/Other | Market Yield | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 16,125 10,330
Level 3 | Equity/Other | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 20,100 26,748
Level 3 | Equity/Other | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 12,530 12,528
Level 3 | Equity/Other | Tangible Net Asset Value Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 224,143 205,980
Level 3 | Equity/Other | Adjusted BV Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 3,967 1,615
Level 3 | FBLC Senior Loan Fund, LLC    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value 218,207 224,956
Level 3 | FBLC Senior Loan Fund, LLC | Discount Rate | Discounted Cash Flow    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Investments at Fair Value $ 218,207 $ 224,956
Level 3 | Minimum | Senior Secured First Lien Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.0000 0.0000
Level 3 | Minimum | Senior Secured First Lien Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 4.90 3.83
Level 3 | Minimum | Senior Secured First Lien Debt | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.09 0.19
Level 3 | Minimum | Senior Secured Second Lien Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.0915 0.1140
Level 3 | Minimum | Senior Secured Second Lien Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 6.75 6.86
Level 3 | Minimum | Senior Secured Second Lien Debt | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input   0.4
Level 3 | Minimum | Subordinated Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1472 0.1427
Level 3 | Minimum | Subordinated Debt | Market Yield | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1174 0.1025
Level 3 | Minimum | Subordinated Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 8.70 0.0983
Level 3 | Minimum | Subordinated Debt | Tangible Net Asset Value Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 1.15 1.15
Level 3 | Minimum | Collateralized Securities | Discount Margin | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1670 0.0000
Level 3 | Minimum | Collateralized Securities | Asset Recovery | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.51  
Level 3 | Minimum | Collateralized Securities | Asset Price | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input   0.20
Level 3 | Minimum | Equity/Other | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.0400 0.1159
Level 3 | Minimum | Equity/Other | Market Yield | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1174 0.1025
Level 3 | Minimum | Equity/Other | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.0226 2.58
Level 3 | Minimum | Equity/Other | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.0018 0.0019
Level 3 | Minimum | Equity/Other | Tangible Net Asset Value Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 1.15 1.15
Level 3 | Minimum | Equity/Other | Adjusted BV Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 3.12 3.92
Level 3 | Minimum | FBLC Senior Loan Fund, LLC | Discount Rate | Discounted Cash Flow    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1144 0.1122
Level 3 | Maximum | Senior Secured First Lien Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.2600 0.3369
Level 3 | Maximum | Senior Secured First Lien Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 17.34 15.57
Level 3 | Maximum | Senior Secured First Lien Debt | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.90 0.62
Level 3 | Maximum | Senior Secured Second Lien Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.2012 0.2450
Level 3 | Maximum | Senior Secured Second Lien Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 17.34 15.57
Level 3 | Maximum | Senior Secured Second Lien Debt | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input   0.4
Level 3 | Maximum | Subordinated Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1905 0.1427
Level 3 | Maximum | Subordinated Debt | Market Yield | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1174 0.1025
Level 3 | Maximum | Subordinated Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 10.75 0.105
Level 3 | Maximum | Subordinated Debt | Tangible Net Asset Value Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 1.45 1.56
Level 3 | Maximum | Collateralized Securities | Discount Margin | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.5000 0.1690
Level 3 | Maximum | Collateralized Securities | Asset Recovery | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.51  
Level 3 | Maximum | Collateralized Securities | Asset Price | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input   0.49
Level 3 | Maximum | Equity/Other | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1165 0.2180
Level 3 | Maximum | Equity/Other | Market Yield | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1174 0.1025
Level 3 | Maximum | Equity/Other | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.2484 25.5
Level 3 | Maximum | Equity/Other | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.009 0.012
Level 3 | Maximum | Equity/Other | Tangible Net Asset Value Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 1.45 1.56
Level 3 | Maximum | Equity/Other | Adjusted BV Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 3.12 3.92
Level 3 | Maximum | FBLC Senior Loan Fund, LLC | Discount Rate | Discounted Cash Flow    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1144 0.1122
Level 3 | Weighted Average | Senior Secured First Lien Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1011 0.1025
Level 3 | Weighted Average | Senior Secured First Lien Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 7.26 8.44
Level 3 | Weighted Average | Senior Secured First Lien Debt | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.28 0.3
Level 3 | Weighted Average | Senior Secured Second Lien Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1109 0.1326
Level 3 | Weighted Average | Senior Secured Second Lien Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 10.54 10.43
Level 3 | Weighted Average | Senior Secured Second Lien Debt | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input   0.4
Level 3 | Weighted Average | Subordinated Debt | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1861 0.1427
Level 3 | Weighted Average | Subordinated Debt | Market Yield | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1174 0.1025
Level 3 | Weighted Average | Subordinated Debt | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 8.70 0.0983
Level 3 | Weighted Average | Subordinated Debt | Tangible Net Asset Value Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 1.32 1.38
Level 3 | Weighted Average | Collateralized Securities | Discount Margin | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1847 0.1690
Level 3 | Weighted Average | Collateralized Securities | Asset Recovery | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.51  
Level 3 | Weighted Average | Collateralized Securities | Asset Price | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input   0.46
Level 3 | Weighted Average | Equity/Other | Market Yield | Yield Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.0768 0.1675
Level 3 | Weighted Average | Equity/Other | Market Yield | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1174 0.1025
Level 3 | Weighted Average | Equity/Other | EBITDA Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1448 12.51
Level 3 | Weighted Average | Equity/Other | Revenue Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.0032 0.0065
Level 3 | Weighted Average | Equity/Other | Tangible Net Asset Value Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 1.34 1.41
Level 3 | Weighted Average | Equity/Other | Adjusted BV Multiple | Waterfall Analysis    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 3.12 3.92
Level 3 | Weighted Average | FBLC Senior Loan Fund, LLC | Discount Rate | Discounted Cash Flow    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Measurement input 0.1144 0.1122
[1] Percentages are based on net assets attributable to common stock as of June 30, 2026.
[2] Unless otherwise indicated, all investments in the consolidated schedules of investments are non-affiliated, non-controlled investments.
[3] Unless otherwise indicated, all of the Company's investments or a portion thereof are pledged as collateral under the JPM Revolver Facility.
[4] Percentages are based on net assets attributable to common stock as of December 31, 2025.
[5] Unless otherwise indicated, all investments in the consolidated schedules of investments are non-affiliated, non-controlled investments.
[6] Unless otherwise indicated, all of the Company's investments or a portion thereof are pledged as collateral under the JPM Revolver Facility (as defined below).