Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Decrease (increase) in current assets:
Receivables, net	$ (1,307)	$ 74
Inventories	(1,134)	(285)
Prepaid expenses and other	(65)	138
Increase (decrease) in current liabilities:
Accounts payable	1,890	227
Accrued expenses	(168)	121
Taxes other than income taxes payable	(32)	78
Income taxes payable	(358)	191
Changes in current assets and current liabilities	(1,174)	544
Cash Flows Related to Interest and Income Taxes
Interest paid in excess of amount capitalized	344	356
Income taxes paid, net	1,116	357
Capital Lease Obligations [Member]
Supplemental Cash Flow Information (Textual)
Capital lease obligations incurred		490
Assets Held under Capital Leases [Member]
Supplemental Cash Flow Information (Textual)
Capital lease assets recognized		490
MVP Terminal [Member]
Supplemental Cash Flow Information (Textual)
Terminal obligations incurred	160	55
MVP Terminal [Member] | Construction in Progress [Member]
Supplemental Cash Flow Information (Textual)
Terminal assets recognized	$ 160	$ 55