Stockholders' Equity (Schedule of Adjustments to Accumulated Other Comprehensive Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss), net [Line Items]
As of December 31, 2018			$ (247)
Other comprehensive income (loss) before reclassifications			(53)
Amounts reclassified from accumulated other comprehensive income (loss)			(5)
Income tax (provision) benefit	$ (2)	$ (4)	(1)	$ 7
As of September 30, 2019	(306)		(306)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss), net [Line Items]
As of December 31, 2018			(236)
Other comprehensive income (loss) before reclassifications			(3)
Amounts reclassified from accumulated other comprehensive income (loss)			0
Income tax (provision) benefit			(8)
As of September 30, 2019	(247)		(247)
Gain (Loss) from Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss), net [Line Items]
As of December 31, 2018			(8)
Other comprehensive income (loss) before reclassifications			(50)
Amounts reclassified from accumulated other comprehensive income (loss)			(5)
Income tax (provision) benefit			7
As of September 30, 2019	(56)		(56)
Pension and Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss), net [Line Items]
As of December 31, 2018			(3)
Other comprehensive income (loss) before reclassifications			0
Amounts reclassified from accumulated other comprehensive income (loss)			0
Income tax (provision) benefit			0
As of September 30, 2019	$ (3)		$ (3)