Derivatives - Net Change in Fair Value of Credit Derivatives Gains (Losses) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Credit Derivatives
Fair value gains (losses) on derivatives	$ 5	$ 1	$ 7	$ 105
Credit
Credit Derivatives
Realized gains (losses) and other settlements (1)	1	0	3	105
Net unrealized gains (losses)	1	1	0	0
Fair value gains (losses) on derivatives	2	1	3	105
Cross-currency swaps
Credit Derivatives
Fair value gains (losses) on derivatives	2	0	(4)	0
Interest rate swaps
Credit Derivatives
Fair value gains (losses) on derivatives	0	0	(1)	0
Inflation swaps
Credit Derivatives
Fair value gains (losses) on derivatives	(3)	0	2	0
Funds withheld - embedded derivative
Credit Derivatives
Fair value gains (losses) on derivatives	$ 4	$ 0	$ 7	$ 0

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.