Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Decrease (increase) in current assets:
Receivables, net	$ (467)	$ 77
Inventories	422	(19)
Income taxes receivable	169	79
Prepaid expenses and other	14	7
Increase (decrease) in current liabilities:
Accounts payable	1,090	575
Accrued expenses	(113)	(75)
Taxes other than income taxes	7	15
Income taxes payable	8	(44)
Changes in current assets and current liabilities	1,130	615
Cash Flows Related to Interest and Income Taxes
Interest paid in excess of amount capitalized	213	202
Income taxes paid, net	137	1,079
Supplemental Cash Flow Elements (Textual)
Other financing activities, net	$ 137	$ (16)