Stockholders' Equity (Schedule of Adjustments to Accumulated Other Comprehensive Income (Loss), Net) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss), net [Line Items]
As of December 31, 2014			$ (165)
Other comprehensive income (loss) before reclassifications			(118)
Amounts reclassified from accumulated other comprehensive income (loss)			5
Income tax (provision) benefit	$ 7	$ (2)	(3)	$ 10
As of June 30, 2015	(281)		(281)
Unrealized Gain (Loss) on Marketable Securities [Member]
Accumulated Other Comprehensive Income (Loss), net [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			(1)
As of June 30, 2015	0		0
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss), net [Line Items]
As of December 31, 2014			(151)
Other comprehensive income (loss) before reclassifications			(117)
Amounts reclassified from accumulated other comprehensive income (loss)			0
Income tax (provision) benefit			(2)
As of June 30, 2015	(270)		(270)
Gain (Loss) from Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss), net [Line Items]
As of December 31, 2014			(4)
Other comprehensive income (loss) before reclassifications			(1)
Amounts reclassified from accumulated other comprehensive income (loss)			5
Income tax (provision) benefit			(1)
As of June 30, 2015	(1)		(1)
Pension and Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss), net [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			1
As of June 30, 2015	$ (10)		$ (10)