Financial Instruments - Net Realized And Unrealized Gains And Losses On Derivative Instruments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Net realized gain (loss) on foreign currency forward contracts	$ 3	$ 2	$ 7	$ 9
Net change in unrealized appreciation (depreciation) on foreign currency forward contracts	$ 0	$ 15	(3)	31
Total			4	40
Foreign Exchange Forward
Derivative Instruments, Gain (Loss) [Line Items]
Net realized gain (loss) on foreign currency forward contracts			7	9
Net change in unrealized appreciation (depreciation) on foreign currency forward contracts			$ (3)	$ 31