Income Taxes (Reconciliation To Effective Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Expected federal income tax expense (benefit)	$ 1,068	$ 1,015	$ 2,270
Non-taxable investment income	(270)	(246)	(369)
Foreign taxes at other than U.S. rate	225	349	(249)
Low-income housing and other tax credits	(118)	(112)	(126)
Changes in tax law	0	(321)	(2,858)
Other	42	137	(106)
Total income tax expense (benefit) on income (loss) before equity in earnings of operating joint ventures	$ 947	$ 822	$ (1,438)
Effective tax rate	18.60%	17.00%	(22.20%)