Sales and Other Operating Revenue - Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue from contracts with customers	$ 4,386	$ 7,756	$ 13,293	$ 24,859
Revenue, Performance Obligation, Description of Payment Terms			The payments are not directly related to our performance under the contract and are recorded as deferred revenue to be recognized as revenue when the customer can utilize and benefit from their right to use the license.
Customers within the scope of ASC Topic 606 [Member]
Revenue from contracts with customers	3,078	6,240	$ 9,908	19,932
Physical gas contracts [Member]
Revenue from contracts with customers	1,280	1,529	3,432	4,981
Crude oil product line [Member]
Revenue from contracts with customers	100	266	218	619
Natural Gas Product Line [Member]
Revenue from contracts with customers	1,042	1,159	2,895	4,022
Other Products [Member]
Revenue from contracts with customers	138	104	319	340
Financial Derivative Contracts [Member]
Revenue from contracts with customers	28	(13)	(47)	(54)
Lower 48 Segment \| Physical gas contracts [Member]
Revenue from contracts with customers	1,018	1,099	2,692	3,823
Canada Segment [Member] \| Physical gas contracts [Member]
Revenue from contracts with customers	152	86	452	427
Europe, Middle East and North Africa [Member] \| Physical gas contracts [Member]
Revenue from contracts with customers	$ 110	$ 344	$ 288	$ 731

Revenue, Performance Obligation, Description of Payment Terms

The payments are not directly related to our performance under the contract and are recorded as deferred revenue to be recognized as revenue when the customer can utilize and benefit from their right to use the license.