Investments - Schedule of Unrealized Net Capital Gains and Losses Included in AOCI (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Fair value
Fixed income securities, at fair value	$ 52,576	$ 48,865
Short-term investments	5,288	5,144
Derivative instruments	0	0
Gross Unrealized Gains
Fixed income securities	292	650
Short-term investments	0	0
Derivative instruments	0	0
Gross Unrealized Losses
Fixed income securities	(1,504)	(1,434)
Short-term investments	(2)	(1)
Derivative instruments	(2)	(2)
Unrealized net gains (losses)
Fixed income securities	(1,212)	(784)
Short-term investments	(2)	(1)
Derivative instruments	(2)	(2)
Limited partnership interests	0	(4)
Unrealized net capital gains and losses, pre-tax	(1,216)	(791)
Amounts recognized for:
Reclassification of noncontrolling interest	12	13
Deferred income taxes	266	174
Unrealized net capital gains and losses, after-tax	$ (938)	$ (604)