Sales and Other Operating Revenues (Revenue from Contracts with Customers) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue from contracts with customers	$ 45,828	$ 18,784	$ 32,567
Revenue, Performance Obligation, Description of Payment Terms	Payment is typically due within 30 days or less.
Customers within the scope of ASC Topic 606 [Member]
Revenue from contracts with customers	$ 34,590	13,662	26,106
Physical gas contracts [Member]
Revenue from contracts with customers	11,500	5,177	6,558
Crude oil product line [Member]
Revenue from contracts with customers	757	395	804
Natural Gas Product Line [Member]
Revenue from contracts with customers	10,034	4,339	5,313
Other Products [Member]
Revenue from contracts with customers	709	443	441
Financial Derivative Contracts [Member]
Revenue from contracts with customers	(262)	(55)	(97)
Lower 48 Segment | Physical gas contracts [Member]
Revenue from contracts with customers	9,050	3,966	4,989
Canada Segment [Member] | Physical gas contracts [Member]
Revenue from contracts with customers	1,457	727	691
Europe, Middle East and North Africa [Member]
Revenue from contracts with customers	5,902	1,919	5,101
Europe, Middle East and North Africa [Member] | Physical gas contracts [Member]
Revenue from contracts with customers	$ 993	$ 484	$ 878