Income Taxes (Reconciliation Of Income Tax Expense Computed At The Statutory Federal Income Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Amount at statutory rate, amount	$ 1,257	$ 1,064	$ 1,387
Amount at statutory rate, percent	21.00%	21.00%	35.00%
State and local income taxes net of federal tax expense/benefit, amount	$ 138	$ 63	$ (2)
State and local income taxes net of federal tax expense/benefit, percent	2.30%	1.20%	(0.10%)
Tax exempt interest and dividends received deduction, amount	$ (24)	$ (27)	$ (58)
Tax exempt interest and dividends received deduction, percent	(0.40%)	(0.50%)	(1.40%)
Health Insurance Provider fee, amount	$ 0	$ 324	$ 0
Health Insurance Provider fee, percent	0.00%	6.40%	0.00%
Tax Cuts and Jobs Act, amount	$ 0	$ (28)	$ (1,108)
Tax Cuts and Jobs Act, percent	0.00%	(0.60%)	(27.90%)
Other, net amount	$ (193)	$ (78)	$ (98)
Other, net percent	(3.20%)	(1.50%)	(2.50%)
Total income tax expense	$ 1,178	$ 1,318	$ 121
Total income tax expense, percent	19.70%	26.00%	3.10%