Income Taxes (Schedule Of Income Tax Expense/(Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	$ 1,193	$ 2,102	$ 676
Non-U.S.	133	122	91
U.S. state	15	21	69
Total Current Income Tax Expense (Benefit)	1,341	2,245	836
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	(618)	(297)	828
Non-U.S.	(4)	4	34
U.S. state	(46)	27	(7)
Total deferred	(668)	(266)	855
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Total income tax expense	$ 673	$ 1,979	$ 1,691