v3.19.3

Income Taxes (Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Contingency [Line Items]
Income tax expense	$ 21	$ 128	$ 40	$ 78
Effective Income Tax Rate, Continuing Operations	4.00%	32.00%	4.00%	75.00%
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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