Investments - Schedule of Unrealized Net Capital Gains and Losses Included in AOCI (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Fair value
Fixed income securities, at fair value	$ 51,993	$ 52,747
Short-term investments	6,541	4,537
Derivative instruments	0	0
Gross Unrealized Gains
Fixed income securities	536	361
Short-term investments	0	0
Derivative instruments	0	0
Gross Unrealized Losses
Fixed income securities	(883)	(1,230)
Short-term investments	(3)	(2)
Derivative instruments	(2)	(2)
Unrealized net gains (losses)
Fixed income securities	(347)	(869)
Short-term investments	(3)	(2)
Derivative instruments	(2)	(2)
Investments classified as held for sale	(91)	(110)
Unrealized net capital gains and losses, pre-tax	(443)	(983)
Amounts recognized for:
Reclassification of noncontrolling interest	(1)	3
Deferred income taxes	93	209
Unrealized net capital gains and losses, after-tax	$ (351)	$ (771)