Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Decrease (increase) in current assets:
Receivables, net	$ 1,396	$ (467)
Inventories	123	422
Income taxes receivable	45	169
Prepaid expenses and other	41	14
Increase (decrease) in current liabilities:
Accounts payable	(942)	1,090
Accrued expenses	262	(113)
Taxes other than income taxes	(41)	7
Income taxes payable	(25)	8
Changes in current assets and current liabilities	859	1,130
Supplemental Cash Flow Elements (Textual)
Payment of long-term liability to joint venture partner	21	134
Cash Flows Related to Interest and Income Taxes
Interest paid in excess of amount capitalized	235	213
Income taxes paid, net	$ 263	137
Owner-Method Joint Venture Investment [Member]
Supplemental Cash Flow Elements (Textual)
Payment of long-term liability to joint venture partner		$ 137