Stockholders' Equity (Schedule of Components of Other Comprehensive Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss), net [Line Items]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	$ 1	$ 0	$ 1	$ 1
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	0	0	0	0
Unrealized gain (loss) on marketable securities	1	0	1	1
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	71	(17)	99	53
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	7	(1)	7	(7)
Foreign currency translation	78	(18)	106	46
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Cash Flow Hedges Arising During Period, before Tax	1	1	(1)	1
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Cash Flow Hedges Arising During Period, Tax	0	0	0	0
Gain (loss) on cash flow hedges	1	1	(1)	1
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	0	(1)	5	(1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	0	0	0	0
Pension and postretirement benefits	0	(1)	5	(1)
Other Comprehensive Income (Loss), before Tax	73	(17)	104	54
Income tax (provision) benefit	7	(1)	7	(7)
Total other comprehensive income (loss), net of tax	$ 80	$ (18)	$ 111	$ 47