Distributions - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended						9 Months Ended
	Nov. 04, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Schedule of Distributions [Line Items]
Distributions declared per share (in USD per share)		$ 0.67	$ 0.68	$ 0.63	$ 0.65	$ 0.60	$ 0.60	$ 1.98	$ 1.85
Percent of market price								95.00%
Capital loss carryforwards		$ 1,877						$ 1,877
Unrealized appreciation		1,321						1,321		$ 1,665
Unrealized depreciation		2,348						2,348		1,995
Income tax purposes		17,638						17,638		17,167
Net unrealized appreciation (depreciation)		(1,846)						(1,846)		$ (1,066)
Subsidiaries
Schedule of Distributions [Line Items]
Deferred tax liability		14						14
Deferred tax asset		60						60
Deferred tax asset offset by valuation allowance		$ 48						48
Deferred income tax								2
Current income tax								$ 1
Subsequent Event
Schedule of Distributions [Line Items]
Distributions declared per share (in USD per share)	$ 0.68