Discontinued Operations (Amounts Reported as Discontinued Operations in the Consolidated Statements of Comprehensive Earnings) Parenthetical (Details) - USD ($) $ in Millions		3 Months Ended	9 Months Ended
		Sep. 30, 2020	Sep. 30, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Asset impairments	[1]	$ 3	$ 182
Barnett Shale [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Asset impairments			$ 182

[1] Devon recognized $182 million of asset impairments in the first nine months of 2020 related to the Barnett Shale assets primarily due to the difference between the net carrying value and the purchase price, net of estimated customary purchase price adjustments, which qualified as a level 2 fair value measurement.