v3.19.2

Income Taxes (Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Contingency [Line Items]
Income tax expense (benefit)	$ 9	$ (158)	$ 19	$ (50)
Effective Income Tax Rate, Continuing Operations	3.00%	(81.00%)	4.00%	17.00%
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits	$ 29		$ 29
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	17		17
Unrecognized Tax Benefit Related to Deferred Tax Asset	12		12
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	3		3
Minimum [Member]
Income Tax Contingency [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	0		0
Maximum [Member]
Income Tax Contingency [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 8		$ 8

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