v3.26.3
Borrowings - Additional Information (Detail) - USD ($)
$ in Thousands
9 Months Ended 12 Months Ended
Dec. 17, 2025
Jun. 23, 2025
Feb. 27, 2025
Mar. 21, 2024
Jul. 03, 2023
Apr. 03, 2023
Sep. 30, 2026
Dec. 31, 2025
Sep. 17, 2025
Jul. 25, 2025
May 14, 2025
Jan. 15, 2025
Oct. 31, 2024
May 01, 2023
Debt Instrument [Line Items]                            
Commitment fee payable percentage             1.25%              
Percentage of commitement for calculating additional fees on unused facility             100.00%              
2025 Notes | Level 2                            
Debt Instrument [Line Items]                            
Fair Value of Notes Outstanding             $ 173,965 $ 174,082            
2024 Notes | Level 2                            
Debt Instrument [Line Items]                            
Fair Value of Notes Outstanding             $ 174,139 174,261            
2025 Note Purchase Agreement | Maximum [Member]                            
Debt Instrument [Line Items]                            
Debt Instrument, Interest Rate, Increase (Decrease)             2.00%              
Collateralized Loan Obligations [Member]                            
Debt Instrument [Line Items]                            
Accounts Receivable from Securitization                 $ 298,870     $ 300,360    
SPV II Revolving Credit Facility [Member] | Goldman Sachs Bank [Member]                            
Debt Instrument [Line Items]                            
Amount of aggregate commitments             $ 250,000              
Spv III Revolving Credit Facility [Member] | Wells Fargo Second Amendment [Member]                            
Debt Instrument [Line Items]                            
Line of credit facility unused commitement fees percentage             35.00%              
Line of credit additional percentage of fees payable unused commitement             2.00%              
Spv III Revolving Credit Facility [Member] | Wells Fargo [Member]                            
Debt Instrument [Line Items]                            
Outstanding debt obligations     $ 650,000               $ 750,000      
Spv III Revolving Credit Facility [Member] | Wells Fargo Bank [Member]                            
Debt Instrument [Line Items]                            
Outstanding debt obligations     $ 900,000                      
Amount of aggregate commitments             $ 250,000              
Spv III Revolving Credit Facility [Member] | Wells Fargo Bank [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Amount of aggregate commitments                         $ 400,000  
SPV V Revolving Credit Facility [Member] | JP Morgan Chase Bank [Member]                            
Debt Instrument [Line Items]                            
Amount of aggregate commitments             $ 250,000              
GS SPV VII Credit Facility [Member] | Goldman Sachs Bank [Member]                            
Debt Instrument [Line Items]                            
Debt instrument, increase (decrease) for period             in each case occurring prior to September 14, 2028, in an amount equal to (i) 2% of the applicable amount if such reduction or acceleration occurs on or prior to September 14, 2027 and (ii) 1% of the applicable amount if such reduction or acceleration occurs thereafter and on or prior to September 14, 2028.              
Tranche A Notes Due Two Thousand Twenty Eight [Member]                            
Debt Instrument [Line Items]                            
Debt instrument floor rate percentage             5.94%              
Notional amount             $ 75,000              
Tranche A Notes Due Two Thousand Twenty Eight [Member] | 2025 Note Purchase Agreement                            
Debt Instrument [Line Items]                            
Aggregate Principle Committed $ 75,000                          
Debt instrument floor rate percentage 5.94%                          
Maturity Date Dec. 17, 2028                          
Tranche B Notes Due Two Thousand Twenty Nine [Member]                            
Debt Instrument [Line Items]                            
Debt instrument floor rate percentage             2.542%              
Notional amount             $ 75,000              
Tranche B Notes Due Two Thousand Twenty Nine [Member] | 2025 Note Purchase Agreement                            
Debt Instrument [Line Items]                            
Aggregate Principle Committed $ 75,000                          
Debt instrument floor rate percentage 5.94%                          
Maturity Date Mar. 17, 2029                          
Tranche C Notes Due Two Thousand Thirty [Member]                            
Debt Instrument [Line Items]                            
Debt instrument floor rate percentage             2.7955%              
Notional amount             $ 75,000              
Tranche C Notes Due Two Thousand Thirty [Member] | 2025 Note Purchase Agreement                            
Debt Instrument [Line Items]                            
Aggregate Principle Committed $ 75,000                          
Debt instrument floor rate percentage 6.32%                          
Maturity Date Dec. 17, 2030                          
Tranche D Notes Due Two Thousand Thirty One [Member]                            
Debt Instrument [Line Items]                            
Debt instrument floor rate percentage             2.7925%              
Notional amount             $ 75,000              
Tranche D Notes Due Two Thousand Thirty One [Member] | 2025 Note Purchase Agreement                            
Debt Instrument [Line Items]                            
Aggregate Principle Committed $ 75,000                          
Debt instrument floor rate percentage 6.32%                          
Maturity Date Mar. 17, 2031                          
Tranche A | Unsecured Notes | Level 3                            
Debt Instrument [Line Items]                            
Fair Value of Notes Outstanding             72,786 74,962            
Tranche B | Unsecured Notes | Level 3                            
Debt Instrument [Line Items]                            
Fair Value of Notes Outstanding             72,499              
Tranche C | Unsecured Notes | Level 3                            
Debt Instrument [Line Items]                            
Fair Value of Notes Outstanding             71,171 $ 74,905            
Tranche D | Unsecured Notes | Level 3                            
Debt Instrument [Line Items]                            
Fair Value of Notes Outstanding             70,975              
Secured Overnight Financing Rate [Member] | Mass Mutual SPV I Revolving Credit Facility [Member] | Massacheuts Mutual Life Insurance Company [Member]                            
Debt Instrument [Line Items]                            
Outstanding debt obligations           $ 200,000 $ 250,000              
Debt instument variable interest rate spread             3.25%              
Debt instrument floor rate percentage             1.00%              
Pledge as a percentage of equity interest held           100.00%                
Line of credit facility unused commitement fees percentage           0.40% 2.00%              
Percentage of maximum commitement amount for calculating utilisation fee           75.00%                
Percentage of maximum commitment for calculating unutilization fee             0.50%              
Line of credit additional percentage of fees payable unused commitement             65.00%              
Percentage of commitement for calculating additional fees on unused facility             0.50%              
Secured Overnight Financing Rate [Member] | Mass Mutual SPV I Revolving Credit Facility [Member] | Massacheuts Mutual Life Insurance Company [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Percentage of maximum commitment for calculating unutilization fee             35.00%              
Secured Overnight Financing Rate [Member] | SPV II Revolving Credit Facility [Member] | Bank of Montreal [Member]                            
Debt Instrument [Line Items]                            
Outstanding debt obligations   $ 162,500   $ 109,500 $ 100,750                 $ 81,250
Debt instument variable interest rate spread   2.35%   2.50%                    
Pledge as a percentage of equity interest held             100.00%              
Line of credit facility expiration date             May 01, 2030              
Estimated additional credit facility             $ 100,000              
Amount of increase in maximum commitments of the credit facility         $ 125,000                  
Secured Overnight Financing Rate [Member] | Spv III Revolving Credit Facility [Member] | Wells Fargo Bank [Member]                            
Debt Instrument [Line Items]                            
Line of credit facility unused commitement fees percentage     2.15%                      
Outstanding Principle             $ 0              
Line of credit additional percentage of fees payable unused commitement             65.00%              
Secured Overnight Financing Rate [Member] | Spv III Revolving Credit Facility [Member] | Wells Fargo Bank [Member] | Minimum [Member]                            
Debt Instrument [Line Items]                            
Debt instrument floor rate percentage               0.00%            
Line of credit facility unused commitement fees percentage             2.25%              
Secured Overnight Financing Rate [Member] | Spv III Revolving Credit Facility [Member] | Wells Fargo Bank [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Debt instrument floor rate percentage             2.15%              
Line of credit facility unused commitement fees percentage             2.65%              
Secured Overnight Financing Rate [Member] | Spv III Revolving Credit Facility [Member] | JP Morgan Chase Bank [Member]                            
Debt Instrument [Line Items]                            
Outstanding Principle             $ 0              
Secured Overnight Financing Rate [Member] | SPV V Revolving Credit Facility [Member] | JP Morgan Chase Bank [Member]                            
Debt Instrument [Line Items]                            
Debt instrument floor rate percentage             0.00%              
Line of credit facility unused commitement fees percentage             0.60%              
Line of Credit Facility, Interest Rate at Period End                   1.85%        
Line of credit facility, interest rate during period             1.90%              
Percentage of Borrowing Base Advance Rate             62.50%              
Percentage of Voluntary Prepayment of Advance Commitment             1.00%              
Secured Overnight Financing Rate [Member] | SPV V Revolving Credit Facility [Member] | JP Morgan Chase Bank [Member] | Minimum [Member]                            
Debt Instrument [Line Items]                            
Line of credit facility expiration date             Jul. 25, 2028              
Secured Overnight Financing Rate [Member] | SPV V Revolving Credit Facility [Member] | JP Morgan Chase Bank [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Line of credit facility expiration date             Jul. 25, 2030              
Secured Overnight Financing Rate [Member] | GS SPV VII Credit Facility [Member] | Goldman Sachs Bank [Member]                            
Debt Instrument [Line Items]                            
Line of credit facility unused commitement fees percentage             0.60%              
Secured Overnight Financing Rate [Member] | GS SPV VII Credit Facility [Member] | Goldman Sachs Bank [Member] | Minimum [Member]                            
Debt Instrument [Line Items]                            
Debt instrument floor rate percentage             0.00%              
Secured Overnight Financing Rate [Member] | GS SPV VII Credit Facility [Member] | Goldman Sachs Bank [Member] | Maximum [Member]                            
Debt Instrument [Line Items]                            
Debt instrument floor rate percentage             1.90%              
Secured Overnight Financing Rate [Member] | Tranche A Notes Due Two Thousand Twenty Eight [Member]                            
Debt Instrument [Line Items]                            
Floating interest rate             2.525%              
Secured Overnight Financing Rate [Member] | Tranche B Notes Due Two Thousand Twenty Nine [Member]                            
Debt Instrument [Line Items]                            
Floating interest rate             5.94%              
Secured Overnight Financing Rate [Member] | Tranche C Notes Due Two Thousand Thirty [Member]                            
Debt Instrument [Line Items]                            
Floating interest rate             6.32%              
Secured Overnight Financing Rate [Member] | Tranche D Notes Due Two Thousand Thirty One [Member]                            
Debt Instrument [Line Items]                            
Floating interest rate             6.32%