Investments - Unrealized net capital gains and losses included in AOCI (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Fair value
Fixed income securities	$ 44,103	$ 42,485
Short-term investments	6,722	4,173
Derivative instruments	0	0
Gross unrealized Gains
Fixed income securities	211	92
Short-term investments	0	0
Derivative instruments	0	0
Gross unrealized Losses
Fixed income securities	(2,228)	(2,977)
Short-term investments	0	(1)
Derivative instruments	(2)	(3)
Unrealized net gains (losses)
Fixed income securities	(2,017)	(2,885)
Short-term investments	0	(1)
Derivative instruments	(2)	(3)
Equity method of accounting limited partnerships	4	2
Unrealized net capital gains and losses, pre-tax	(2,015)	(2,887)
Amounts recognized for:
Other unrealized net capital gains and losses, pre-tax	18	23
Deferred income taxes	424	609
Unrealized net capital gains and losses, after-tax	$ (1,573)	$ (2,255)