Fair Value of Financial Instruments - Changes in Fair Value of Investments Using Level 3 Inputs (Details) - USD ($)
$ in Thousands |
3 Months Ended |
9 Months Ended |
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Balance, beginning of period |
$ 3,175,716
|
$ 3,217,112
|
$ 3,181,834
|
$ 3,485,041
|
| Purchases or originations |
271,052
|
289,266
|
618,852
|
718,671
|
| Repayments / redemptions |
(163,054)
|
(313,181)
|
(471,303)
|
(980,760)
|
| Sales Proceeds |
(10)
|
(1,588)
|
|
(46,696)
|
| Paid-in-kind interest |
6,891
|
6,847
|
17,997
|
17,704
|
| Net change in unrealized gains (losses) |
$ 3,020
|
$ (10,518)
|
$ (18,613)
|
$ 39,704
|
| Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] |
Unrealized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax
|
Unrealized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax
|
Unrealized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax
|
Unrealized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax
|
| Net realized gains (losses) |
$ (15,865)
|
$ 779
|
$ (58,599)
|
$ (37,051)
|
| Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] |
Realized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax
|
Realized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax
|
Realized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax
|
Realized Gain (Loss), Investment, Derivative, and Foreign Currency Transaction, Operating, after Tax
|
| Net amortization of discount on securities |
$ 4,864
|
$ 6,544
|
$ 12,728
|
$ 20,666
|
| Transfers into (out of) Level 3 |
|
|
(282)
|
(22,018)
|
| Balance, End of Period |
3,282,614
|
3,195,261
|
3,282,614
|
3,195,261
|
| First-lien Debt Investments |
|
|
|
|
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Balance, beginning of period |
2,901,631
|
3,014,071
|
2,956,297
|
3,287,829
|
| Purchases or originations |
220,203
|
283,139
|
516,576
|
679,358
|
| Repayments / redemptions |
(162,200)
|
(312,964)
|
(461,454)
|
(977,186)
|
| Sales Proceeds |
(10)
|
|
|
(36,910)
|
| Paid-in-kind interest |
4,068
|
4,365
|
9,549
|
11,110
|
| Net change in unrealized gains (losses) |
(10,826)
|
(12,641)
|
(75,585)
|
47,109
|
| Net realized gains (losses) |
(12,865)
|
10
|
(12,855)
|
(41,472)
|
| Net amortization of discount on securities |
4,701
|
6,395
|
12,174
|
20,070
|
| Transfers within Level 3 |
(10,927)
|
|
(10,927)
|
(7,533)
|
| Balance, End of Period |
2,933,775
|
2,982,375
|
2,933,775
|
2,982,375
|
| Second-lien Debt Investments |
|
|
|
|
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Balance, beginning of period |
23,675
|
28,735
|
30,456
|
18,535
|
| Purchases or originations |
|
|
|
15,357
|
| Repayments / redemptions |
|
(217)
|
(8,245)
|
(3,574)
|
| Paid-in-kind interest |
925
|
1,074
|
3,235
|
2,906
|
| Net change in unrealized gains (losses) |
166
|
(725)
|
38,487
|
(4,751)
|
| Net realized gains (losses) |
|
|
(39,489)
|
|
| Net amortization of discount on securities |
127
|
117
|
449
|
511
|
| Balance, End of Period |
24,893
|
28,984
|
24,893
|
28,984
|
| Mezzanine Debt Investments |
|
|
|
|
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Balance, beginning of period |
64,621
|
53,567
|
61,684
|
39,091
|
| Purchases or originations |
|
6,000
|
|
18,740
|
| Repayments / redemptions |
(854)
|
|
(1,604)
|
|
| Paid-in-kind interest |
1,702
|
1,408
|
5,017
|
3,607
|
| Net change in unrealized gains (losses) |
(453)
|
(925)
|
(150)
|
(1,441)
|
| Net amortization of discount on securities |
36
|
32
|
105
|
85
|
| Transfers within Level 3 |
(1,086)
|
|
(1,086)
|
|
| Balance, End of Period |
63,966
|
60,082
|
63,966
|
60,082
|
| Equity and Structured Credit Investments |
|
|
|
|
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Balance, beginning of period |
131,957
|
|
133,397
|
|
| Purchases or originations |
26,599
|
|
26,635
|
|
| Paid-in-kind interest |
196
|
|
196
|
|
| Net change in unrealized gains (losses) |
12,225
|
|
14,286
|
|
| Net realized gains (losses) |
(3,000)
|
|
(6,255)
|
|
| Transfers within Level 3 |
12,013
|
|
12,013
|
|
| Transfers into (out of) Level 3 |
|
|
(282)
|
|
| Balance, End of Period |
179,990
|
|
179,990
|
|
| Equity Investments |
|
|
|
|
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Balance, beginning of period |
|
120,739
|
|
139,586
|
| Purchases or originations |
|
127
|
|
5,216
|
| Sales Proceeds |
|
(1,588)
|
|
(9,786)
|
| Paid-in-kind interest |
|
|
|
81
|
| Net change in unrealized gains (losses) |
|
3,773
|
|
(1,213)
|
| Net realized gains (losses) |
|
769
|
|
4,421
|
| Transfers within Level 3 |
|
|
|
7,533
|
| Transfers into (out of) Level 3 |
|
|
|
(22,018)
|
| Balance, End of Period |
|
$ 123,820
|
|
$ 123,820
|
| Joint Venture Investments |
|
|
|
|
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Balance, beginning of period |
53,832
|
|
|
|
| Purchases or originations |
24,250
|
|
75,641
|
|
| Net change in unrealized gains (losses) |
1,908
|
|
4,349
|
|
| Balance, End of Period |
$ 79,990
|
|
$ 79,990
|
|