Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Earnings (loss) from continuing operations before income taxes	$ (193)	$ 190	$ (2,980)	$ (88)
Current income tax expense (benefit)	(90)	2	(199)	1
Deferred income tax expense (benefit)		52	(311)	2
Total income tax expense (benefit)	$ (90)	$ 54	$ (510)	$ 3
U.S. statutory income tax rate	21.00%	21.00%	21.00%	21.00%
State income taxes	0.00%	6.00%	1.00%	(2.00%)
Change in tax legislation	4.00%	0.00%	3.00%	0.00%
Unrecognized tax benefits	18.00%	0.00%	0.00%	(2.00%)
Other	0.00%	1.00%	(1.00%)	(20.00%)
Deferred tax asset valuation allowance	4.00%	0.00%	(7.00%)	0.00%
Effective income tax rate	47.00%	28.00%	17.00%	(3.00%)

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