Joint Ventures - Selected Statement of Operations Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Investment income:
Total investment income	$ 1,456,927	$ 1,044,979	$ 4,199,974	$ 2,337,502
Expenses:
Interest expense	444,235	294,772	1,319,057	566,332
Total expenses before excise tax	669,049	473,797	1,959,223	996,001
Net investment income before excise tax	787,878	571,182	2,240,751	1,341,501
Tax Expense	9,681	0	23,113	292
Net investment income after excise tax	778,197	571,182	2,217,638	1,341,209
Net realized and change in unrealized gain (loss) on investments and other transactions
Net change in unrealized gain (loss)	384,505	(135,308)	552,835	(1,085,983)
Net realized gain (loss)	(134,981)	(99,556)	(307,091)	(110,874)
Net realized and unrealized gain (loss)	249,524	(234,864)	245,744	(1,196,857)
Net increase (decrease) in net assets resulting from operations	1,027,721	336,318	2,463,382	144,352
Non-controlled/non-affiliated investments
Investment income:
Interest income	1,309,957	970,341	3,816,351	2,150,852
Payment-in-kind interest income	60,593	36,734	152,815	89,526
Dividend income	158	0	158	1,510
Nonconsolidated Investee | BCRED Verdelite JV LP
Investment income:
Total investment income	11,027		32,754
Expenses:
Interest expense	6,478		17,604
Other expenses	474		624
Total expenses before excise tax	6,952		18,228
Net investment income before excise tax	4,075		14,526
Tax Expense	0		0
Net investment income after excise tax	4,075		14,526
Net realized and change in unrealized gain (loss) on investments and other transactions
Net change in unrealized gain (loss)	2,313		11,183
Net realized gain (loss)	724		2,152
Net realized and unrealized gain (loss)	3,037		13,335
Net increase (decrease) in net assets resulting from operations	7,112		27,861
Nonconsolidated Investee | BCRED Verdelite JV LP | Non-controlled/non-affiliated investments
Investment income:
Interest income	10,965		32,578
Other income	62		176
Nonconsolidated Investee | BCRED Emerald JV LP
Investment income:
Total investment income	166,251	57,121	493,605	120,290
Expenses:
Interest expense	62,213	18,762	179,728	32,957
Other expenses	933	1,404	3,801	2,616
Total expenses before excise tax	63,146	20,166	183,529	35,573
Net investment income before excise tax	103,105	36,955	310,076	84,717
Tax Expense	0	0	0	0
Net investment income after excise tax	103,105	36,955	310,076	84,717
Net realized and change in unrealized gain (loss) on investments and other transactions
Net change in unrealized gain (loss)	30,618	(7,970)	68,374	(58,771)
Net realized gain (loss)	(1,623)	(2,259)	(7,767)	(2,750)
Net realized and unrealized gain (loss)	28,995	(10,229)	60,607	(61,521)
Net increase (decrease) in net assets resulting from operations	132,100	26,726	370,683	23,196
Nonconsolidated Investee | BCRED Emerald JV LP | Non-controlled/non-affiliated investments
Investment income:
Interest income	164,464	56,971	486,577	119,898
Payment-in-kind interest income	1,665	0	5,127	0
Dividend income	49	0	394	0
Other income	$ 73	$ 150	$ 1,507	$ 392