Net Earnings (Loss) Per Share from Continuing Operations (Earnings Per Share Computations from Continuing Operations) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net earnings (loss) from continuing operations:
Net earnings (loss) from continuing operations		$ (474)	$ 212	$ (685)	$ 520
Attributable to participating securities		(1)	(3)	(1)	(6)
Basic and diluted earnings (loss) from continuing operations		$ (475)	$ 209	$ (686)	$ 514
Common shares:
Common shares outstanding - total		521	526	524	525
Attributable to participating securities		(6)	(6)	(6)	(6)
Common shares outstanding - basic		515	520	518	519
Dilutive effect of potential common shares issuable			3		3
Common shares outstanding - diluted		515	523	518	522
Net earnings (loss) per share from continuing operations:
Basic		$ (0.92)	$ 0.40	$ (1.33)	$ 0.99
Diluted		$ (0.92)	$ 0.40	$ (1.33)	$ 0.99
Antidilutive options	[1]	2	2	2	2

[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.