Supplemental Cash Flow Information - Schedule of Activities Resulting from Management of Proceeds (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Net change in proceeds managed
Net change in fixed income securities	$ (468)	$ (210)
Net change in short-term investments	328	114
Operating cash flow (used)	(140)	(96)
Net change in liabilities
Liabilities for collateral, beginning of period	(1,934)	(2,041)
Liabilities for collateral, end of period	(2,074)	(2,137)
Operating cash flow provided	$ 140	$ 96