Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash Flows from Operating Activities
Net Increase (Decrease) in Net Assets Resulting from Operations	$ 594,980	$ 793,312	$ 466,355
Adjustments to reconcile net increase (decrease) in net assets resulting from operations to net cash provided by (used in) operating activities:
Purchases of investments, net	(5,536,243)	(2,268,603)	(2,132,632)
Proceeds from investments and investment repayments, net	5,155,245	2,889,840	1,926,108
Net amortization/accretion of premium/discount on investments	(68,198)	(49,349)	(41,712)
Payment-in-kind interest and dividends	(245,116)	(209,984)	(147,758)
Net change in unrealized (gain) loss on investments	48,419	(91,743)	88,427
Net change in unrealized gain (loss) on interest rate swap attributed to unsecured notes	6,792	22,681	(84,779)
Net change in unrealized (gains) losses on translation of assets and liabilities in foreign currencies	925	(5,768)	2,514
Net realized (gain) loss on investments	60,626	52,003	(5,171)
Net realized (gain) loss on foreign currency transactions relating to investments	16,504	23	3,586
Amortization of debt issuance costs	30,661	26,849	30,076
Cash acquired in OBDC SLF LLC consolidation	62,461	0	0
Changes in operating assets and liabilities:
(Increase) decrease in interest receivable	13,543	(4,175)	(26,369)
(Increase) decrease in receivable from a controlled affiliate	6,008	(5,269)	(13,756)
(Increase) decrease in prepaid expenses and other assets	(14,321)	475	20,089
Increase (decrease) in management fee payable	1,347	128	813
Increase (decrease) in incentive fee payable	(3,135)	7,755	5,220
Increase (decrease) in payables to affiliate	(4,063)	(2,516)	549
Increase (decrease) in accrued expenses and other liabilities	33,780	(20,048)	125,708
Net cash provided by (used in) operating activities	160,215	1,135,611	217,268
Cash Flows from Financing Activities
Borrowings on debt	4,182,592	1,746,479	2,531,427
Payments on debt	(3,799,219)	(2,007,393)	(2,220,889)
Debt issuance costs	(33,532)	(12,694)	(15,484)
Repurchases of common stock	0	(34,058)	(25,958)
Cash distributions paid to shareholders	(655,558)	(613,374)	(488,422)
Net cash provided by (used in) financing activities	(305,717)	(921,040)	(219,326)
Net increase (decrease) in cash and restricted cash, including foreign cash (restricted cash of $(4,680), $(9,353) and $74,939, respectively)	(145,502)	214,571	(2,058)
Cash and restricted cash, including foreign cash, beginning of period (restricted cash of $87,067, $96,420 and $21,481, respectively)	659,658	445,087	447,145
Cash and restricted cash, including foreign cash, end of period (restricted cash of $82,387, $87,067 and $96,420, respectively)	514,156	659,658	445,087
Supplemental and Non-Cash Information
Interest paid during the period	418,700	396,732	234,195
Distributions declared during the period	670,954	620,264	507,822
Reinvestment of distributions during the period	7,422	0	11,951
Distributions Payable	144,381	136,407	129,517
Taxes, including excise tax, paid during the period	$ 6,139	$ 3,448	$ 3,913