Investments (Realized Investment Gains Losses, Net) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Gain (Loss) on Securities [Line Items]
Realized investment gains (losses), net	$ 432	$ (79)	$ 3,146	$ (2,164)
Fixed maturities
Gain (Loss) on Securities [Line Items]
Realized investment gains (losses), net	221	401	1,750	671
Commercial mortgage and other loans
Gain (Loss) on Securities [Line Items]
Realized investment gains (losses), net	67	41	158	65
Investment real estate
Gain (Loss) on Securities [Line Items]
Realized investment gains (losses), net	49	5	113	15
LPs/LLCs
Gain (Loss) on Securities [Line Items]
Realized investment gains (losses), net	(43)	8	(26)	2
Derivatives
Gain (Loss) on Securities [Line Items]
Realized investment gains (losses), net	131	(537)	1,145	(2,926)
Other
Gain (Loss) on Securities [Line Items]
Realized investment gains (losses), net	$ 7	$ 3	$ 6	$ 9