Supplementary Financial Information Supplemental Financial Information (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Accounts receivable	$ 482	$ 628
Allowance for doubtful accounts	(3)	(3)
Accounts receivable, net	479	625
Foreign Exchange Contracts	0	23
Other	24	41
Prepaid expenses and other current assets	24	64
Accrued incentive compensation	101	52
Customer reserves	41	50
Accrued payroll	50	51
Interest payable	15	20
Accrued other expenses	130	150
Accrued liabilities	$ 337	$ 323