Financial Instruments - Net Realized And Unrealized Gains And Losses On Derivative Instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Net realized gain (loss) on foreign currency forward contracts	$ 1	$ 2	$ 4	$ 7
Net change in unrealized appreciation (depreciation) on foreign currency forward contracts	$ 1	$ 15	(3)	16
Total			1	23
Foreign Exchange Forward
Derivative Instruments, Gain (Loss) [Line Items]
Net realized gain (loss) on foreign currency forward contracts			4	7
Net change in unrealized appreciation (depreciation) on foreign currency forward contracts			$ (3)	$ 16