Stockholders' Equity (Schedule of Adjustments to Accumulated Other Comprehensive Income (Loss), Net) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2012	$ (89)	[1]
Other comprehensive income, before reclassifications	(31)
Amounts reclassified from accumulated other comprehensive income	2
Income tax (provision) benefit	(1)		(4)	[1]
As of March 31, 2013	(119)
Unrealized Gain (Loss) on Marketable Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2012	(1)
Other comprehensive income, before reclassifications	0
Amounts reclassified from accumulated other comprehensive income	0
Income tax (provision) benefit	0
As of March 31, 2013	(1)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2012	(23)
Other comprehensive income, before reclassifications	(31)
Amounts reclassified from accumulated other comprehensive income	0
Income tax (provision) benefit	0
As of March 31, 2013	(54)
Gain (Loss) on Interest Rate Swaps [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2012	(50)
Other comprehensive income, before reclassifications	0
Amounts reclassified from accumulated other comprehensive income	2	[2]
Income tax (provision) benefit	(1)
As of March 31, 2013	(49)
Pension and Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2012	15	[1]
Other comprehensive income, before reclassifications	0
Amounts reclassified from accumulated other comprehensive income	0	[3]
Income tax (provision) benefit	0
As of March 31, 2013	$ 15

[1] As Adjusted (Note 1)

[2] This accumulated other comprehensive income component is related to interest rate swaps and is included in interest expense (Note 15).

[3] This accumulated other comprehensive income component is the amortization of prior service cost included in net periodic benefit cost (Note 10).