Other Financial Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	$ 47	$ 64
Other	79	50
Total other current assets	126	114
Accounts payable	440	456
Capital expenditures incurred but not yet paid	$ 11	$ 27