Income Taxes (Schedule Of Income Tax Expense/(Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	$ (308)	$ 1,873	$ 1,276
Non-U.S.	169	169	149
U.S. state	(161)	97	23
Total Current Income Tax Expense (Benefit)	(300)	2,139	1,448
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. federal	(953)	(996)	204
Non-U.S.	(3)	(4)	3
U.S. state	(367)	5	(6)
Total deferred	(1,323)	(995)	201
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Total income tax (benefit)/expense	$ (1,623)	$ 1,144	$ 1,649