Revenues and Accounts Receivable - Contract Balances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Change in Contract Liabilities [Roll Forward]
Beginning balance	$ 501	$ 354
Amounts recognized as revenue	(393)	(246)
Additions	33	393
Ending balance	141	501
Crude Oil Sales Agreements Entered Into In Conjunction WIth Storage Arrangements And Future Inventory Exchanges
Change in Contract Liabilities [Roll Forward]
Beginning balance	361
Additions	361	155
Ending balance	$ 0	$ 361