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Fair Value Measurements - Summary of Reconciliation of Beginning and Ending Balances for Fair Valued Investments (Details) - Level 3 - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized appreciation (depreciation) on investments	$ 1,593	$ (36,403)	$ (4,505)	$ (42,882)
Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			860,019	718,767
Net realized gains (losses) on investments			4,267	65,220
Net change in unrealized appreciation (depreciation) on investments			(143)	(67,774)
Purchase of investments			204,049	267,950
Proceeds from sales and repayments of investments			(146,316)	(128,255)
Interest and dividend income paid-in-kind			4,661	1,327
Proceeds from loan origination fees			(2,098)	(1,869)
Accretion of loan origination fees			1,809	1,094
Accretion of original issue discount			344	137
Ending Balance	926,592	856,597	926,592	856,597
Subordinated Debt | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			101,456	36,064
Net change in unrealized appreciation (depreciation) on investments			(1,314)	1,213
Purchase of investments			29,041	44,469
Proceeds from sales and repayments of investments			(10,149)
Interest and dividend income paid-in-kind			2,343	273
Proceeds from loan origination fees			(541)	(300)
Accretion of loan origination fees			140	40
Accretion of original issue discount			5
Ending Balance	120,981	81,759	120,981	81,759
First Lien Debt | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			456,105	354,922
Net change in unrealized appreciation (depreciation) on investments			(1,576)	(1,281)
Purchase of investments			135,283	166,279
Proceeds from sales and repayments of investments			(68,761)	(31,574)
Interest and dividend income paid-in-kind			850	481
Proceeds from loan origination fees			(1,226)	(1,454)
Accretion of loan origination fees			1,563	943
Accretion of original issue discount			51	18
Ending Balance	522,289	488,334	522,289	488,334
Second Lien Debt | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			182,948	158,815
Net realized gains (losses) on investments			(9,333)
Net change in unrealized appreciation (depreciation) on investments			3,226	(13,048)
Purchase of investments			25,000	49,498
Proceeds from sales and repayments of investments			(48,607)	(18,731)
Interest and dividend income paid-in-kind			1,468	573
Proceeds from loan origination fees			(331)	(115)
Accretion of loan origination fees			106	111
Accretion of original issue discount			288	119
Ending Balance	154,765	177,222	154,765	177,222
Equity | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			117,431	165,762
Net realized gains (losses) on investments			13,600	65,220
Net change in unrealized appreciation (depreciation) on investments			(1,976)	(54,102)
Purchase of investments			14,725	7,704
Proceeds from sales and repayments of investments			(18,799)	(77,950)
Ending Balance	124,981	106,634	124,981	106,634
Warrant | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			2,079	3,204
Net change in unrealized appreciation (depreciation) on investments			1,497	(556)
Ending Balance	$ 3,576	$ 2,648	$ 3,576	$ 2,648

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Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

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