Equity (Components of Net Unrealized Appreciation Depreciation of Balances Carried at Fair Value) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Comprehensive Income Net Of Tax [Line Items]
Fixed maturity securities available-for-sale		$ 51,121	$ 39,992
Other invested assets		2,363	1,915
Deferred policy acquisition costs		(3,512)	(3,398)	$ (3,240)	$ (3,339)
Accumulated Other Comprehensive Income Loss Change In Component During Period		3,123	(1,712)	1,005
Change In Net Unrealized Appreciation Depreciation [Member]
Comprehensive Income Net Of Tax [Line Items]
Fixed maturity securities available-for-sale		3,258	(1,759)	988
Other invested assets	[1]	(37)	20	25
Effect On Unrealized Appreciation Depreciation [Member]
Comprehensive Income Net Of Tax [Line Items]
Deferred policy acquisition costs		$ (98)	$ 27	$ (8)

[1] Includes cash flow hedges. See Note 5 for additional information on cash flow hedges.