Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net Investment Income [Line Items]
Total investment income	$ 95,218	$ 96,684	$ 250,976	$ 263,219
Expenses:
Interest and other debt expenses	21,979	14,449	53,823	43,953
Incentive fees	0	9,326	12,023	32,551
Management fees	9,157	7,962	26,933	24,241
Professional fees	814	724	2,559	2,257
Directors' fees	209	234	616	698
Other general and administrative expenses	1,041	793	3,301	2,691
Total expenses	33,200	33,488	99,255	106,391
Fee waivers		(1,441)	(11,724)	(24,192)
Net expenses	33,200	32,047	87,531	82,199
Net investment income before taxes	62,018	64,637	163,445	181,020
Income tax expense, including excise tax	829	305	2,494	929
Net investment income after taxes	61,189	64,332	160,951	180,091
Net realized gain (loss) from:
Non-controlled/non-affiliated investments		(1,606)	(5,054)	4,628
Non-controlled affiliated investments		35,916		35,916
Controlled affiliated investments			(2,035)
Foreign currency forward contracts	90	(49)	171	(220)
Foreign currency and other transactions	(1,565)	69	(2,413)	113
Net change in unrealized appreciation (depreciation) from:
Non-controlled/non-affiliated investments	(50,069)	(21,412)	(89,028)	(20,534)
Non-controlled affiliated investments	(3,529)	(39,257)	(1,585)	(47,279)
Controlled affiliated investments	(18,685)	(1,391)	(19,746)	(3,566)
Foreign currency forward contracts	(35)	122	11	396
Foreign currency translations and other transactions	4,974	1,392	10,051	4,234
Net realized and unrealized gains (losses)	(68,819)	(26,216)	(109,628)	(26,312)
(Provision) benefit for taxes on realized gain/loss on investment				(53)
(Provision) benefit for taxes on unrealized appreciation/depreciation on investments	130	(83)	12	(253)
Net increase (decrease) in net assets from operations	$ (7,500)	$ 38,033	$ 51,335	$ 153,473
Weighted average shares outstanding	102,367,005	101,727,464	102,069,593	101,654,241
Net investment income per share (basic and diluted)	$ 0.60	$ 0.63	$ 1.58	$ 1.77
Earnings per share basic	(0.07)	0.37	0.50	1.51
Earnings per share diluted	$ (0.07)	$ 0.37	$ 0.50	$ 1.51
From Non-controlled/ Non-affiliated Investments
Net Investment Income [Line Items]
Interest income	$ 88,326	$ 90,043	$ 231,605	$ 246,570
Payment-in-kind	5,154	4,768	14,266	11,179
Other income	1,384	1,101	3,550	2,717
From Non-controlled Affiliated Investments
Net Investment Income [Line Items]
Dividend income	133	90	258	916
Interest income		23	16	69
Payment-in-kind	101	175	553	478
From controlled Affiliated Investments
Net Investment Income [Line Items]
Interest income	$ 120	119	469	282
Payment-in-kind		$ 365	$ 259	$ 1,008