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Fair Value Measurements - Summary of Reconciliation of Beginning and Ending Balances for Fair Valued Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Realized gain (loss) on investment	Realized gain (loss) on investment
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Change In Unrealized (appreciation) Depreciation on Investments	Net Change In Unrealized (appreciation) Depreciation on Investments
Transfers in/(out) of Level 3	$ 0	$ 1
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized appreciation (depreciation) on investments	(28,524)	46,340
Level 3 | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	718,767	742,869
Net realized gains (losses) on investments	65,635	55,808
Net change in unrealized appreciation (depreciation) on investments	(65,655)	41,496
Purchase of investments	333,846	346,737
Proceeds from sales and repayments of investments	(193,980)	(472,782)
Interest and dividend income paid-in-kind	1,663	4,399
Proceeds from loan origination fees	(2,124)	(2,670)
Accretion of loan origination fees	1,625	2,512
Accretion of original issue discount	242	755
Transfers in/(out) of Level 3		(357)
Ending Balance	860,019	718,767
Subordinated Debt | Level 3 | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	36,064	107,911
Net realized gains (losses) on investments	0
Net change in unrealized appreciation (depreciation) on investments	753	(499)
Purchase of investments	66,516	16,500
Proceeds from sales and repayments of investments	(2,000)	(88,384)
Interest and dividend income paid-in-kind	415	92
Proceeds from loan origination fees	(350)	(135)
Accretion of loan origination fees	58	579
Accretion of original issue discount	0	0
Transfers in/(out) of Level 3		0
Ending Balance	101,456	36,064
First Lien Debt | Level 3 | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	354,922	187,353
Net realized gains (losses) on investments	(1,717)
Net change in unrealized appreciation (depreciation) on investments	904	(1,152)
Purchase of investments	189,149	244,596
Proceeds from sales and repayments of investments	(87,622)	(75,124)
Interest and dividend income paid-in-kind	597	292
Proceeds from loan origination fees	(1,566)	(2,322)
Accretion of loan origination fees	1,412	1,279
Accretion of original issue discount	26	0
Transfers in/(out) of Level 3		0
Ending Balance	456,105	354,922
Second Lien Debt | Level 3 | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	158,815	332,154
Net realized gains (losses) on investments	0
Net change in unrealized appreciation (depreciation) on investments	(20,948)	35
Purchase of investments	67,998	72,181
Proceeds from sales and repayments of investments	(23,731)	(250,662)
Interest and dividend income paid-in-kind	651	3,911
Proceeds from loan origination fees	(208)	(213)
Accretion of loan origination fees	155	654
Accretion of original issue discount	216	755
Transfers in/(out) of Level 3		0
Ending Balance	182,948	158,815
Equity | Level 3 | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	165,762	112,836
Net realized gains (losses) on investments	65,817	55,779
Net change in unrealized appreciation (depreciation) on investments	(45,610)	42,652
Purchase of investments	10,183	13,331
Proceeds from sales and repayments of investments	(78,721)	(58,583)
Interest and dividend income paid-in-kind	0	104
Proceeds from loan origination fees	0	0
Accretion of loan origination fees	0	0
Accretion of original issue discount	0	0
Transfers in/(out) of Level 3		(357)
Ending Balance	117,431	165,762
Warrant | Level 3 | Fair Value, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	3,204	2,615
Net realized gains (losses) on investments	1,535	29
Net change in unrealized appreciation (depreciation) on investments	(754)	460
Purchase of investments	0	129
Proceeds from sales and repayments of investments	(1,906)	(29)
Interest and dividend income paid-in-kind	0	0
Proceeds from loan origination fees	0	0
Accretion of loan origination fees	0	0
Accretion of original issue discount	0	0
Transfers in/(out) of Level 3		0
Ending Balance	$ 2,079	$ 3,204

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Indicates line item in statement in which net income is reported that includes unrealized gain (loss) from asset measured at fair value using unobservable input (level 3) and still held.

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

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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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