Stockholders' Equity (Schedule of Components of Other Comprehensive Income (Loss), Net) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Comprehensive Income (Loss) [Line Items]
Unrealized gain (loss) on marketable securities, gross amount	$ 0	$ 0	$ 0
Unrealized gain (loss) on marketable securities, income tax (provision) benefit	0	0	1
Unrealized gain (loss) on marketable securities, net amount	0	0	1
Foreign currency translation, gross amount	(22)	(193)	(188)
Foreign currency translation, income tax (provision) benefit	11	5	40
Foreign currency translation, net amount	(11)	(188)	(148)
Gain (loss) on cash flow hedges, gross amount	5	3	0
Gain (loss) on cash flow hedges, income tax (provision) benefit	0	(1)	40
Gain (loss) on cash flow hedges, net amount	5	2	40
Pension and postretirement benefits, gross amount	(5)	4	(84)
Pension and postretirement benefits, income tax (provision) benefit	1	(1)	30
Pension and postretirement benefits, net amount	(4)	3	(54)
Total other comprehensive income (loss), gross amount	(22)	(186)	(272)
Total other comprehensive income (loss), income tax (provision) benefit	12	3	111
Total other comprehensive income (loss), net of tax	$ (10)	$ (183)	$ (161)