Commitments and Contingencies (Details) $ in Millions		6 Months Ended		22 Months Ended	25 Months Ended	28 Months Ended
	Jan. 01, 2019 USD ($)	Jun. 30, 2019 USD ($) bbl / d renewal	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) bbl / d renewal	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Commitments and Contingencies (Textual)
MVP Terminal construction costs		$ 43,110		$ 43,110			$ 42,473
Contributions to MVP		90	$ 119
Cost of undivided interest in pipeline		$ 29	$ 145
MVP Terminalling, LLC (MVP) [Member]
Commitments and Contingencies (Textual)
Initial term of terminal agreement		12 years
Number of available automatic renewals | renewal		2		2
Automatic renewal term of terminalling agreement		5 years
MVP Terminal [Member]
Commitments and Contingencies (Textual)
Contributions to MVP		$ 83		$ 330
Equity investment in MVP		$ 330		$ 330
MVP Terminal [Member] | Topic 842 [Member]
Commitments and Contingencies (Textual)
Derecognized assets related to MVP	$ 539
Derecognized liability related to MVP	292
Equity investment in MVP recorded due to derecognition of assets and liabilities	$ 247
MVP Terminal [Member] | Magellan Midstream Partners LP (Magellan) [Member]
Commitments and Contingencies (Textual)
Long-term liability recorded							292
MVP Terminal [Member] | Expected [Member]
Commitments and Contingencies (Textual)
Contributions to MVP						$ 420
MVP Terminal [Member] | Construction in Progress [Member]
Commitments and Contingencies (Textual)
MVP Terminal construction costs							$ 539
MVP Terminal [Member] | Minimum [Member] | Construction in Progress [Member] | Expected [Member]
Commitments and Contingencies (Textual)
MVP Terminal construction costs						840
MVP Terminal [Member] | Maximum [Member] | Construction in Progress [Member] | Expected [Member]
Commitments and Contingencies (Textual)
MVP Terminal construction costs						$ 1,400
Central Texas Pipeline [Member]
Commitments and Contingencies (Textual)
Undivided interest in project (percent)		40.00%		40.00%
Pipeline capacity (in barrels per day) | bbl / d		150,000		150,000
Cost of undivided interest in pipeline		$ 29		$ 109
Central Texas Pipeline [Member] | Expected [Member]
Commitments and Contingencies (Textual)
Cost of undivided interest in pipeline					$ 170
Variable Interest Entity, Not Primary Beneficiary [Member] | MVP Terminalling, LLC (MVP) [Member]
Commitments and Contingencies (Textual)
Membership percentage in VIE (percent)		50.00%
Variable Interest Entity, Not Primary Beneficiary [Member] | MVP Terminalling, LLC (MVP) [Member] | Expected [Member]
Commitments and Contingencies (Textual)
Membership percentage in VIE (percent)						50.00%