This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8813-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Commitments and Contingencies (Details) $ in Millions		9 Months Ended		25 Months Ended	28 Months Ended
Commitments and Contingencies (Details) $ in Millions	Jan. 01, 2019 USD ($)	Sep. 30, 2019 USD ($) bbl / d renewal	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) bbl / d renewal	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Commitments and Contingencies (Textual)
MVP Terminal construction costs		$ 43,539		$ 43,539		$ 42,473
Contributions to MVP		122	$ 124
Cost of undivided interest in pipeline		$ 65	$ 181
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		$ 115		$ 362
Equity investment in MVP		$ 362		$ 362
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		$ 65		$ 160
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%