Consolidated Statements of Changes in Net Assets - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Partners' Capital [Abstract]
Net assets at beginning of period	$ 1,580,445	$ 1,609,951	$ 1,502,394	$ 1,614,400
Increase (decrease) in net assets from operations:
Net investment income	64,502	49,612	112,488	99,762
Net realized gain (loss)	(2,958)	(4,449)	(39,019)	(7,856)
Net change in unrealized appreciation (depreciation)	4,290	(26,600)	20,814	(32,953)
(Provision) benefit for taxes on unrealized appreciation/depreciation on investments	(170)	114	(556)	(118)
Net increase (decrease) in net assets from operations	65,664	18,677	93,727	58,835
Distributions to stockholders from:
Distributable earnings	(49,259)	(45,934)	(98,517)	(91,782)
Total distributions to stockholders	(49,259)	(45,934)	(98,517)	(91,782)
Capital transactions:
Issuance of common stock (net of offering and underwriting costs)		1,793	97,556	1,793
Reinvestment of stockholder distributions		1,185	1,690	2,426
Net increase in net assets from capital transactions		2,978	99,246	4,219
Total increase (decrease) in net assets	16,405	(24,279)	94,456	(28,728)
Net assets at end of period	$ 1,596,850	$ 1,585,672	$ 1,596,850	$ 1,585,672
Distributions per share	$ 0.45	$ 0.45	$ 0.9	$ 0.9