Consolidated Statements of Changes in Net Assets - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Increase (Decrease) in Net Assets Resulting from Operations
Net investment income (loss)		$ 753,611	$ 556,718	$ 490,137
Net change in unrealized gain (loss)		92,946	(94,509)	179,824
Net realized gain (loss)		(53,245)	4,146	(45,079)
Net Increase (Decrease) in Net Assets Resulting from Operations		793,312	466,355	624,882
Distributions
Distributions declared from earnings	[1]	(620,264)	(507,822)	(486,868)
Capital Share Transactions
Repurchase of common shares		(34,058)	(25,958)	(2,604)
Reinvestment of distributions		0	11,951	56,033
Net Increase (Decrease) in Net Assets Resulting from Capital Share Transactions		(34,058)	(14,007)	53,429
Total Increase (Decrease) in Net Assets		138,990	(55,474)	191,443
Net Assets, at beginning of period		5,882,403	5,937,877	5,746,434
Net Assets, at end of period		$ 6,021,393	$ 5,882,403	$ 5,937,877

[1] (1)For the year ended December 31, 2023 distributions declared from earnings were derived from net investment income and capital gains. For the year ended December 31, 2022, distributions declared from earnings were derived from net investment income. For the year ended December 31, 2021 distributions declared from earnings were derived from net investment income and capital gains.