Supplemental Balance Sheet and Cash Flow Information - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions				12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in Working Capital [Abstract]
Change in accounts receivable				$ (141)	$ (86)	$ 0
Change in inventories				(146)	(13)	(28)
Change in accounts payable				234	70	(22)
Change in accrued payroll and employee benefits				53	5	3
Change in accrued income taxes				26	(13)	(1)
Change in other current assets and liabilities				(34)	(14)	7
Net				(8)	(51)	(41)
Supplemental Cash Flow Information [Abstract]
Interest paid				104	111	96
Income taxes paid				87	89	90
Purchases of property, plant and equipment held in accounts payable	$ 86	$ 113	$ 55
Non-cash financing activity related to stock compensation plans				$ 17	$ 14	$ 15