Stockholders' Equity (Schedule of Adjustments to Accumulated Other Comprehensive Income (Loss), Net) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2013	$ (4)
Other comprehensive income, before reclassifications	(3)
Amounts reclassified from accumulated other comprehensive income	(19)
Income tax (provision) benefit	12	(1)
As of March 31, 2014	(14)
Unrealized Gain (Loss) on Marketable Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2013	0
Other comprehensive income, before reclassifications	0
Amounts reclassified from accumulated other comprehensive income	0
Income tax (provision) benefit	0
As of March 31, 2014	0
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2013	(3)
Other comprehensive income, before reclassifications	(3)
Amounts reclassified from accumulated other comprehensive income	0
Income tax (provision) benefit	8
As of March 31, 2014	2
Gain (Loss) on Interest Rate Swaps [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2013	(44)
Other comprehensive income, before reclassifications	0
Amounts reclassified from accumulated other comprehensive income	0
Income tax (provision) benefit	(3)
As of March 31, 2014	(47)
Pension and Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
As of December 31, 2013	43
Other comprehensive income, before reclassifications	0
Amounts reclassified from accumulated other comprehensive income	(19)
Income tax (provision) benefit	7
As of March 31, 2014	$ 31