Investments, Investment Gains (Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Investment Gains (Losses) [Abstract]
Gain (Loss) on Investments	$ 660	$ (1,246)	$ 49
Nonredeemable Preferred Stock
Investment Gains (Losses) [Abstract]
Gain (Loss) on Investments	2	(3)	66
Total fixed maturities
Investment Gains (Losses) [Abstract]
Gross gains	186	220	125
Gross losses	(90)	(220)	(131)
Gain (Loss) on Investments	96	0	(6)
Equity securities
Investment Gains (Losses) [Abstract]
Gain (Loss) on Investments	4	(3)	66
Derivative instruments
Investment Gains (Losses) [Abstract]
Gain (Loss) on Investments	6	(10)	(11)
Short term investments and other
Investment Gains (Losses) [Abstract]
Gain (Loss) on Investments	14	(22)
Altium Packaging LLC
Investment Gains (Losses) [Abstract]
Deconsolidation loss	555
Diamond Offshore Drilling Inc.
Investment Gains (Losses) [Abstract]
Deconsolidation loss	$ (15)	$ (1,211)