Consolidated Statements of Changes in Net Assets (Unaudited) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Beginning balance		$ 1,582,006	$ 1,496,375	$ 1,356,005	$ 1,341,569	$ 1,496,375	$ 1,341,569
Net investment income		55,143	52,362	48,784	42,937	107,506	91,721
Net change in unrealized gains (losses) on investments and foreign currency translation		(9,493)	(6,969)	2,822	4,777	(16,462)	7,599
Net realized gains (losses) on investments and foreign currency transactions		1,751	2,125	1,484	5,238	$ 3,875	$ 6,722
Issuance of common stock, net of offering and underwriting costs		11,850	81,457	89,290
Stock issued in connection with dividend reinvestment plan		5,993	5,924	5,581	6,248
Stock issued in connection with dividend reinvestment plan, Shares						587,706	676,944
Dividends declared from distributable earnings		(48,215)	(49,268)	(43,437)	(44,764)
Ending balance		$ 1,599,035	1,582,006	$ 1,460,529	1,356,005	$ 1,599,035	$ 1,460,529
Ending balance,Shares		93,017,205		87,241,231		93,017,205	87,241,231
Common Stock
Beginning balance		$ 928	$ 885	$ 824	$ 821	$ 885	$ 821
Beginning balance, Shares		92,121,556	87,829,499	81,751,865	81,389,287	87,829,499	81,389,287
Issuance of common stock, net of offering and underwriting costs		$ 6	$ 40				$ 52
Issuance of common stock, net of offering and underwriting costs, Shares		600,000	4,000,000	5,175,000
Stock issued in connection with dividend reinvestment plan		$ 3	$ 3	$ 3	$ 3
Stock issued in connection with dividend reinvestment plan, Shares		295,649	292,057	314,366	362,578
Ending balance		$ 937	$ 928	$ 879	$ 824	$ 937	$ 879
Ending balance,Shares		93,017,205	92,121,556	87,241,231	81,751,865	93,017,205	87,241,231
Treasury Stock
Beginning balance		$ (10,459)	$ (10,459)	$ (10,459)	$ (10,459)	$ (10,459)	$ (10,459)
Beginning balance, Shares		664,250	664,250	664,250	664,250	664,250	664,250
Ending balance		$ (10,459)	$ (10,459)	$ (10,459)	$ (10,459)	$ (10,459)	$ (10,459)
Ending balance,Shares		664,250	664,250	664,250	664,250	664,250	664,250
Paid in Capital in Excess of Par
Beginning balance		$ 1,492,511	$ 1,405,173	$ 1,300,593	$ 1,294,751	$ 1,405,173	$ 1,294,751
Issuance of common stock, net of offering and underwriting costs		11,844	81,417	89,238
Stock issued in connection with dividend reinvestment plan		5,990	5,921	5,578	6,245
Tax reclassification of stockholders' equity in accordance with GAAP	[1]				(403)
Ending balance		1,510,345	1,492,511	1,395,409	1,300,593	1,510,345	1,395,409
Distributable Earnings
Beginning balance		99,026	100,776	65,047	56,456	100,776	56,456
Net investment income		55,143	52,362	48,784	42,937
Net change in unrealized gains (losses) on investments and foreign currency translation		(9,493)	(6,969)	2,822	4,777
Net realized gains (losses) on investments and foreign currency transactions		1,751	2,125	1,484	5,238
Dividends declared from distributable earnings		(48,215)	(49,268)	(43,437)	(44,764)
Tax reclassification of stockholders' equity in accordance with GAAP	[1]				403
Ending balance		$ 98,212	$ 99,026	$ 74,700	$ 65,047	$ 98,212	$ 74,700

[1] The Company changed its tax year end from March 31st to December 31st.