v3.26.1
Fair Value - Summary of The Changes In Fair Value Of Level 3 Assets (Detail) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Fair Value Recurring Basis Unobservable Input Reconciliation Asset Gain Loss Statement Of Income Extensible List Not Disclosed [Flag] us-gaap:EstimateOfFairValueFairValueDisclosureMember   us-gaap:EstimateOfFairValueFairValueDisclosureMember
Fair Value, Inputs, Level 3 [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Opening balance $ 184,442 $ 316,509  
Net realized gain 0 0  
Net change in unrealized gain (loss) (2,136) (3,272)  
Purchase of investment securities* 8,645 [1] 1,462 [2]  
Proceeds from dispositions of investment securities (11,508) (39,381)  
Transfers into Level 3 0 0  
Transfers out of Level 3 0 0  
Closing balance 179,443 275,318 $ 316,509
Net change in unrealized gain (loss) (2,129) (3,272)  
Bank Debt/Senior Secured Loans | Fair Value, Inputs, Level 3 [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Opening balance 162,467 294,802  
Net realized gain 0 0  
Net change in unrealized gain (loss) (1,259) (790)  
Purchase of investment securities* 4,048 [1] 692 [2]  
Proceeds from dispositions of investment securities (11,508) (39,381)  
Transfers into Level 3 0 0  
Transfers out of Level 3 0 0  
Closing balance 153,748 255,323 294,802
Net change in unrealized gain (loss) (1,252) (790)  
Preferred Equity | Fair Value, Inputs, Level 3 [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Opening balance 11,175 10,223  
Net realized gain 0 0  
Net change in unrealized gain (loss) (759) (38)  
Purchase of investment securities* 4,479 [1] 268 [2]  
Proceeds from dispositions of investment securities 0 0  
Transfers into Level 3 0 0  
Transfers out of Level 3 0 0  
Closing balance 14,895 10,453 10,223
Net change in unrealized gain (loss) (759) (38)  
Common Equity/Equity Interests/Warrants | Fair Value, Inputs, Level 3 [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Opening balance 10,800 11,484  
Net realized gain 0 0  
Net change in unrealized gain (loss) (118) (2,444)  
Purchase of investment securities* 118 [1] 502 [2]  
Proceeds from dispositions of investment securities 0 (0)  
Transfers into Level 3 0 0  
Transfers out of Level 3 0 0  
Closing balance 10,800 9,542 $ 11,484
Net change in unrealized gain (loss) $ (118) $ (2,444)  
[1] Includes PIK capitalization and accretion of discount.
[2] Includes PIK capitalization and accretion of discount.