Income Taxes (Schedule Of Income Tax (Provisions) Benefits Attributable To Income From Continuing Operations) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Deferred income taxes	$ (121)	$ 143	$ (90)	$ 284
Income tax benefit (provision)	$ (121)	$ 143	$ (90)	$ 284
Effective Tax Rate	34.00%	35.00%	32.00%	35.00%
Statutory Tax Rate			35.00%
Effective Income Tax Rate Reconciliation, Deduction, Amount			$ 8
Unrecognized Tax Benefits	$ 119		$ 119		$ 112

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments.

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Amount of unrecognized tax benefits.

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