Income Taxes (Schedule of Effective Tax Rate Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Total pre-tax income (loss) from continuing operations	$ 392	$ 1,427	$ (454)
Total income tax expense (benefit)	$ (88)	$ 331	$ 376
Effective income tax rate (benefit) on continuing operations	(22.00%)	23.00%	83.00%
Income taxes at the statutory tax rate	$ 83	$ 300	$ (159)
Effects of foreign operations	(29)	214	140
Adjustments to valuation allowances	(28)	(177)	446
State income taxes	11	(17)	(19)
Tax law change	0	0	(35)
Other federal tax effects	$ (125)	$ 11	$ 3

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

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