Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Unrecognized Tax Benefits	$ 413		$ 413		$ 427
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 316		$ 316		$ 332
Effective tax rate from continuing operations	(5.90%)	(60.30%)	4.00%	(27.30%)
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 99		$ 99

Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

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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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Amount of unrecognized tax benefits.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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