Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental Cash Flow Information
Interest paid note repurchase premiums	$ 18	$ 9	$ 32
Decrease (increase) in current assets:
Receivables	(37)	(32)	(14)
Inventories	2	16	(13)
Prepaid expenses and other	(10)	145	(4)
Increase (decrease) in current liabilities:
Accounts payable	69	(58)	100
Accrued liabilities	(49)	(31)	21
Salaries and wages	(21)	32	12
U.S. and foreign income taxes	(43)	18	(14)
Changes in components of working capital, total	(89)	90	88
Amount of receivables sold	454	318
Interest paid in cash	261	261	227
Income taxes paid (received) in cash
U.S. Income taxes paid in cash	4
Non-U.S. Income taxes paid in cash	127	99	101
Total income taxes paid in cash	$ 131	$ 99	$ 101