v3.26.3
Borrowings (Additional Information) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended 12 Months Ended
Aug. 25, 2026
Jun. 16, 2025
Mar. 24, 2025
Aug. 25, 2022
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Jul. 09, 2026
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         5.89%   5.89%   6.09%              
Fund's average outstanding debt         $ 872.2 $ 835.3 $ 878.2 $ 863.4                
Debt weighted average interest rate         5.83% 6.46% 5.82% 6.49%                
Minimum [Member]                                
Line of Credit Facility [Line Items]                                
Line of credit facility, minimum asset coverage ratio         150.00%   150.00%   188.00%              
Maximum                                
Line of Credit Facility [Line Items]                                
Line of credit facility, minimum asset coverage ratio         189.00%   189.00%                  
Fidelity Direct Lending Fund I JSPV LLC [Member]                                
Line of Credit Facility [Line Items]                                
Commitment fee percentage       0.525%                        
Aggregate principal amount         $ 700.0 [1]   $ 700.0 [1]   $ 1,000.0 [2]              
Line of Credit Facility, Maximum Borrowing Capacity       $ 500.0                 $ 1,500.0 $ 1,000.0 $ 950.0 $ 750.0
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%                          
Aggregate principal amount         $ 600.0   $ 600.0   $ 430.0     $ 400.0        
Line of credit facility current borrowing capacity   $ 300.0                            
Total facility amount $ 900.0                              
limit for swingline loans   60.0                            
Line of Credit Facility, Maximum Borrowing Capacity   $ 750.0                            
Debt Instrument Maturity Date   Jun. 14, 2030                            
Credit facility expiration and maturity the extension of the Maturity Date from June 14, 2030 to August 25, 2031, (iii) the extension of the Commitment Termination Date from June 15, 2029 to August 23, 2030, The availability period under the Truist Senior Secured Revolving Credit Facility will terminate on June 15, 2029 (the “Commitment Termination Date”) and the Truist Senior Secured Revolving Credit Facility will mature on June 14, 2030 (the “Maturity Date”).                            
Truist Senior Secured Revolving Credit Facility [Member] | Minimum [Member]                                
Line of Credit Facility [Line Items]                                
Aggregate principal amount $ 430.0                   $ 400.0          
Borrowings annual interest rate     1.75%                          
Truist Senior Secured Revolving Credit Facility [Member] | Minimum [Member] | 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]                                
Aggregate principal amount $ 600.0                   $ 430.0          
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%                          
Fifth Amendment [Member] | Minimum [Member]                                
Line of Credit Facility [Line Items]                                
Aggregate principal amount                   $ 700.0            
Fifth Amendment [Member] | Maximum                                
Line of Credit Facility [Line Items]                                
Aggregate principal amount                   1,000.0            
Fifth Amendment [Member] | Tranche B [Member]                                
Line of Credit Facility [Line Items]                                
Aggregate principal amount                   200.0            
Fifth Amendment [Member] | Tranche A [Member] | Minimum [Member]                                
Line of Credit Facility [Line Items]                                
Aggregate principal amount                   500.0            
Fifth Amendment [Member] | Tranche A [Member] | Maximum                                
Line of Credit Facility [Line Items]                                
Aggregate principal amount                   $ 800.0            
[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 September 30, 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.