v3.26.1
Fair Value Measurements - Reconciliation of investments (Details) - USD ($)
$ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Fair Value Measurements    
Beginning Balance $ 2,443,312 $ 2,354,678
Purchases of investments and other adjustments to cost 407,676 1,280,957
Paid-in-kind interest 19,439 33,881
Net accretion of discounts (amortization of premiums) 1,834 5,139
Principal repayments and sales of investments (529,619) (1,231,175)
Net change in unrealized appreciation on investments (544) 28,048
Net realized gain (loss) on investments (24,141) (28,216)
Ending Balance 2,317,957 2,443,312
Change in unrealized appreciation attributable to investments still held (19,782) 456
First Lien Senior Secured Loans    
Fair Value Measurements    
Beginning Balance 1,591,538 1,543,286
Purchases of investments and other adjustments to cost 377,503 1,170,550
Paid-in-kind interest 12,115 19,831
Net accretion of discounts (amortization of premiums) 1,631 4,875
Principal repayments and sales of investments (454,837) (1,132,193)
Net change in unrealized appreciation on investments (17,963) (2,937)
Net realized gain (loss) on investments (15,303) (11,874)
Ending Balance 1,494,684 1,591,538
Change in unrealized appreciation attributable to investments still held (27,987) (14,211)
Second Lien Senior Secured Loans    
Fair Value Measurements    
Beginning Balance 30,020 30,104
Purchases of investments and other adjustments to cost   9,670
Net accretion of discounts (amortization of premiums) 51 64
Principal repayments and sales of investments   (9,597)
Net change in unrealized appreciation on investments (2) 18,817
Net realized gain (loss) on investments   (19,038)
Ending Balance 30,069 30,020
Change in unrealized appreciation attributable to investments still held (2) (62)
Subordinated Debt    
Fair Value Measurements    
Beginning Balance 95,687 53,350
Purchases of investments and other adjustments to cost 3 29,393
Paid-in-kind interest 6,052 10,159
Net accretion of discounts (amortization of premiums) 147 203
Principal repayments and sales of investments (13,733)  
Net change in unrealized appreciation on investments (2,047) (2,486)
Net realized gain (loss) on investments 525  
Reclassifications   5,068
Ending Balance 86,634 95,687
Change in unrealized appreciation attributable to investments still held (1,427) (2,581)
Preferred Equity    
Fair Value Measurements    
Beginning Balance 157,244 170,876
Purchases of investments and other adjustments to cost 18,783 33,316
Paid-in-kind interest 1,272 3,891
Net accretion of discounts (amortization of premiums) 5 3
Principal repayments and sales of investments (1,065) (63,294)
Net change in unrealized appreciation on investments 5,378 6,442
Net realized gain (loss) on investments 1,051 11,078
Reclassifications   (5,068)
Ending Balance 182,668 157,244
Change in unrealized appreciation attributable to investments still held 5,378 13,107
Equity Interests    
Fair Value Measurements    
Beginning Balance 219,124 219,210
Purchases of investments and other adjustments to cost 2,402 14,528
Net accretion of discounts (amortization of premiums)   (6)
Principal repayments and sales of investments (59,984) (26,091)
Net change in unrealized appreciation on investments 17,544 19,865
Net realized gain (loss) on investments (10,414) (8,382)
Ending Balance 168,672 219,124
Change in unrealized appreciation attributable to investments still held 7,710 15,856
Warrants    
Fair Value Measurements    
Beginning Balance 1,045 628
Net change in unrealized appreciation on investments (349) 417
Ending Balance 696 1,045
Change in unrealized appreciation attributable to investments still held (349) 417
Subordinated Note Investment Vehicles    
Fair Value Measurements    
Beginning Balance 348,654 [1] 337,224 [2]
Purchases of investments and other adjustments to cost 8,985 [1] 23,500 [2]
Net change in unrealized appreciation on investments (3,105) (12,070) [2]
Ending Balance [1] 354,534 348,654
Change in unrealized appreciation attributable to investments still held $ (3,105) $ (12,070) [2]
[1] Represents debt investment in ISLP and SLP.
[2] Represents debt investment in ISLP and SLP.