Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Decrease (increase) in current assets:
Receivables, net	$ 74	$ (278)
Inventories	(285)	557
Prepaid expenses and other	138	137
Increase (decrease) in current liabilities:
Accounts payable	227	494
Accrued expenses	121	46
Taxes other than income taxes payable	78	8
Income taxes payable	191	(11)
Changes in current assets and current liabilities	544	953
Supplemental Cash Flow Elements (Textual)
Payment of long-term liability to joint venture partner	21	146
Cash Flows Related to Interest and Income Taxes
Interest paid in excess of amount capitalized	356	312
Income taxes paid, net	$ 357	305
Owner-Method Joint Venture Investment [Member]
Supplemental Cash Flow Elements (Textual)
Payment of long-term liability to joint venture partner		$ 137