Other Financial Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Additional Financial Information Disclosure [Abstract]
Impairment of asset	$ 11	$ 11	$ 0	$ 17
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	48	48	46
Assets held for sale	8	8	0
Other	73	73	77
Total other current assets	129	129	123
Accounts Payable, Current [Abstract]
Accounts payable	$ 398	398	369
Capital expenditures incurred but not yet paid		$ 53	$ 29