Net Earnings (Loss) Per Share from Continuing Operations (Net Earnings (Loss) Per Share Computations from Continuing Operations) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net earnings (loss) from continuing operations:
Net earnings (loss) from continuing operations		$ (2,552)	$ (81)	$ 714
Attributable to participating securities		(4)	(2)	(8)
Basic and diluted earnings (loss) from continuing operations		$ (2,556)	$ (83)	$ 706
Common shares:
Common shares outstanding - total		383	407	499
Attributable to participating securities		(6)	(6)	(5)
Common shares outstanding - basic		377	401	494
Dilutive effect of potential common shares issuable				3
Common shares outstanding - diluted		377	401	497
Net earnings (loss) per share from continuing operations:
Basic		$ (6.78)	$ (0.21)	$ 1.43
Diluted		$ (6.78)	$ (0.21)	$ 1.42
Antidilutive options	[1]		1	1

[1] Amounts represent options to purchase shares of Devon’s common stock that are excluded from the diluted net earnings per share calculations because the options are antidilutive.