v3.26.1
Borrowings (Additional Information) (Details) - USD ($)
3 Months Ended 12 Months Ended
Jun. 16, 2025
Aug. 25, 2022
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Nov. 26, 2025
Aug. 22, 2025
Aug. 06, 2025
Nov. 26, 2024
Jun. 06, 2023
Jan. 24, 2023
Line of Credit Facility [Line Items]                      
Weighted average interest rate paid     5.80%   6.09%            
Line of credit facility, minimum asset coverage ratio     188.00%   188.00%            
Fund's average outstanding debt     $ 893,700,000 $ 876,900,000              
Debt weighted average interest rate     5.82% 6.51%              
Minimum                      
Line of Credit Facility [Line Items]                      
Line of credit facility, minimum asset coverage ratio     150.00%                
Fidelity Direct Lending Fund I JSPV LLC [Member]                      
Line of Credit Facility [Line Items]                      
Commitment fee percentage   0.525%                  
Initial principal amount     $ 1,000,000,000 [1]   $ 1,000,000,000 [2]            
Line of Credit Facility, Maximum Borrowing Capacity   $ 500,000,000           $ 1,500,000,000 $ 1,000,000,000 $ 950,000,000 $ 750,000,000
Debt Instrument Maturity Date     Feb. 25, 2029                
Applicable margin   2.85% 2.20%                
Fidelity Direct Lending Fund I JSPV LLC [Member] | British Pounds                      
Line of Credit Facility [Line Items]                      
Applicable margin   2.97%     2.3193%            
Truist Senior Secured Revolving Credit Facility [Member]                      
Line of Credit Facility [Line Items]                      
Commitment fee percentage 0.375%                    
Initial principal amount     $ 430,000,000   $ 430,000,000   $ 400,000,000        
Line of credit facility current borrowing capacity $ 300,000,000                    
limit for swingline loans 60,000,000                    
Line of Credit Facility, Maximum Borrowing Capacity $ 750,000,000                    
Debt Instrument Maturity Date Jun. 14, 2030                    
Credit facility expiration and maturity The availability period under the Truist Facility will terminate on June 15, 2029 (the “Commitment Termination Date”) and the Truist Facility will mature on June 14, 2030 (the “Maturity Date”).                    
Truist Senior Secured Revolving Credit Facility [Member] | Minimum                      
Line of Credit Facility [Line Items]                      
Initial principal amount           $ 400,000,000          
Borrowings annual interest rate 1.75%                    
Truist Senior Secured Revolving Credit Facility [Member] | Minimum | Base Rate [Member]                      
Line of Credit Facility [Line Items]                      
Borrowings annual interest rate 0.75%                    
Truist Senior Secured Revolving Credit Facility [Member] | Maximum                      
Line of Credit Facility [Line Items]                      
Initial principal amount           $ 430,000,000          
Borrowings annual interest rate 1.875%                    
Truist Senior Secured Revolving Credit Facility [Member] | Maximum | Base Rate [Member]                      
Line of Credit Facility [Line Items]                      
Borrowings annual interest rate 0.875%                    
[1] Under the Fidelity Direct Lending Fund I JSPV LLC Facility, the Fund is permitted to borrow in USD or certain other currencies. As of March 31, 2026, the Fund had borrowings denominated in Canadian Dollars (“CAD”) of 0.5 million, translated to USD of $0.3 million.
[2] Under the Fidelity Direct Lending Fund I JSPV LLC Facility, the Fund is permitted to borrow in USD or certain other currencies. As of December 31, 2025, the Fund had borrowings denominated in Canadian Dollars (“CAD”) of 0.5 million, translated to USD of $0.4 million.