Investments - Investment Gains (Losses) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Investment Gains (Losses) [Abstract]
Investment gains (losses)	$ (59)	$ 578	$ (70)	$ 635
Nonredeemable Preferred Stock
Investment Gains (Losses) [Abstract]
Investment gains (losses)	(70)	15	(108)	15
Fixed maturity securities
Investment Gains (Losses) [Abstract]
Gross gains	45	51	71	109
Gross losses	(60)	(20)	(88)	(40)
Investment gains (losses)	(15)	31	(17)	69
Equity securities
Investment Gains (Losses) [Abstract]
Investment gains (losses)	(71)	17	(109)	19
Derivative instruments
Investment Gains (Losses) [Abstract]
Investment gains (losses)	26	(12)	55	5
Short term investments and other
Investment Gains (Losses) [Abstract]
Investment gains (losses)	1	(13)	1	(13)
Altium Packaging (see Note 1)
Investment Gains (Losses) [Abstract]
Investment gains (losses)		$ 555		$ 555