Stockholders' Equity (Schedule of Adjustments to Accumulated Other Comprehensive Income (Loss), Net) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2014	$ (165)
Other comprehensive income (loss) before reclassifications	(151)
Amounts reclassified from accumulated other comprehensive income (loss)	4
Income tax (provision) benefit	(10)	(12)
As of March 31, 2015	(322)
Unrealized Gain (Loss) on Marketable Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2014	1
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified from accumulated other comprehensive income (loss)	0
Income tax (provision) benefit	0
As of March 31, 2015	1
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2014	(151)
Other comprehensive income (loss) before reclassifications	(150)
Amounts reclassified from accumulated other comprehensive income (loss)	0
Income tax (provision) benefit	(6)
As of March 31, 2015	(307)
Gain (Loss) from Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2014	(4)
Other comprehensive income (loss) before reclassifications	(1)
Amounts reclassified from accumulated other comprehensive income (loss)	4
Income tax (provision) benefit	(1)
As of March 31, 2015	(2)
Pension and Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2014	(11)
Other comprehensive income (loss) before reclassifications	0
Amounts reclassified from accumulated other comprehensive income (loss)	0
Income tax (provision) benefit	(3)
As of March 31, 2015	$ (14)