Leases, Significant Lease Commencement (Details) - USD ($) $ in Millions			3 Months Ended		12 Months Ended
		Apr. 19, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Significant Lease Commencement (Textual)
Finance lease ROU asset and related liability recognized	[1]				$ 378	$ 950	$ 239
Finance lease liability			$ 1,664		$ 1,920	1,664
MVP Terminalling, LLC (MVP) [Member]
Significant Lease Commencement (Textual)
Initial term of terminal agreement					12 years
MVP Terminalling, LLC (MVP) [Member]
Significant Lease Commencement (Textual)
Membership interest (percent)		25.01%			25.01%
MVP Terminal [Member]
Significant Lease Commencement (Textual)
Finance lease ROU asset and related liability recognized				$ 1,400		800
Finance lease liability			800			$ 800
MVP Terminal [Member] | Derecognition due to Remeasurement [Member]
Significant Lease Commencement (Textual)
Finance lease ROU asset and related liability recognized			$ (600)

[1] Noncash activity for the year ended December 31, 2020 primarily included approximately $800 million for a finance lease ROU asset and related liability recognized in connection with the terminaling agreement with MVP described in Note 6. Noncash activity for the year ended December 31, 2019 included $1.3 billion for operating lease ROU assets and related liabilities recorded on January 1, 2019 upon adoption of FASB Accounting Standards Codification Topic 842, “Leases,” (Topic 842).