Stockholders' Equity (Schedule of Components of Other Comprehensive Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss), net [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	$ 45	$ 28
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	4	0
Foreign currency translation	49	28
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Cash Flow Hedges Arising During Period, before Tax	(2)	(2)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Cash Flow Hedges Arising During Period, Tax	1	0
Gain (loss) on cash flow hedges	(1)	(2)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	1	5
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	0	0
Pension and postretirement benefits	1	5
Other Comprehensive Income (Loss), before Tax	44	31
Income tax (provision) benefit	5	0
Total other comprehensive income (loss), net of tax	$ 49	$ 31