Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Decrease (increase) in current assets:
Receivables, net	$ (457)	$ (870)	$ (1,531)
Inventories	(197)	(516)	771
Prepaid expenses and other	(77)	151	47
Increase (decrease) in current liabilities:
Accounts payable	304	1,842	1,556
Accrued expenses	(113)	21	117
Taxes other than income taxes payable	(73)	172	82
Income taxes payable	(684)	489	(66)
Changes in current assets and current liabilities	(1,297)	1,289	976
Cash Flows Related to Interest and Income Taxes
Interest paid in excess of amount capitalized	463	457	427
Income taxes paid, net	1,361	410	444
Supplemental Cash Flow Elements (Textual)
Payment of long-term liability to joint venture partner	15	(20)	178
MVP Terminal [Member]
Supplemental Cash Flow Elements (Textual)
Terminal obligations incurred	198	94
Capital Lease Obligations [Member]
Supplemental Cash Flow Elements (Textual)
Capital lease obligations incurred	63	502
Assets Held under Capital Leases [Member]
Supplemental Cash Flow Elements (Textual)
Capital lease assets recognized	63	502
Construction in Progress [Member] | MVP Terminal [Member]
Supplemental Cash Flow Elements (Textual)
Terminal assets recognized	$ 198	$ 94
Owner-Method Joint Venture Investment [Member]
Supplemental Cash Flow Elements (Textual)
Payment of long-term liability to joint venture partner			$ 137