Supplemental Quarterly Financial Information (Schedule Of Unaudited Interim Results Of Operations) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	[1]	Dec. 31, 2015	[1]
Quarterly Financial Data [Line Items]
Upstream revenues									$ 5,307	$ 3,981		$ 5,885
Marketing and midstream revenues									8,642	6,323		7,260
Total revenues									13,949	10,304		13,145
Production expenses									1,823	1,803		2,439
Exploration expenses									380	215		451
Marketing and midstream expenses									7,730	5,533		6,461
Depreciation, depletion and amortization									2,074	2,096		4,022
Asset impairments									17	1,310		17,647
Asset dispositions									(217)	(1,483)		7
General and administrative expenses									872	865		1,193
Financing costs, net									498	907		519
Other expenses									(124)	375		264
Total expenses									13,053	11,621		33,003
Earnings (loss) before income taxes									896	(1,317)		(19,858)
Income tax expense (benefit)									(182)	141		(6,213)
Net earnings (loss)									1,078	(1,458)		(13,645)
Net earnings attributable to noncontrolling interests									180	(402)		(749)
Net earnings (loss) attributable to Devon									$ 898	$ (1,056)		$ (12,896)
Net earnings per share attributable to Devon:
Basic									$ 1.71	$ (2.09)		$ (31.72)
Diluted									$ 1.70	$ (2.09)		$ (31.72)
Comprehensive earnings:
Net earnings (loss)									$ 1,078	$ (1,458)		$ (13,645)
Other comprehensive earnings, net of tax:
Foreign currency translation and other									83	11		(443)
Pension and postretirement plans									29	22		10
Other comprehensive earnings, net of tax									112	33		(433)
Comprehensive earnings (loss)									1,190	(1,425)		(14,078)
Comprehensive earnings attributable to noncontrolling interests									180	(402)		(749)
Comprehensive earnings (loss) attributable to Devon									$ 1,010	$ (1,023)		$ (13,329)
As Reported Under Sucessful Efforts
Quarterly Financial Data [Line Items]
Upstream revenues	$ 1,333	$ 1,101	$ 1,332	$ 1,541
Marketing and midstream revenues	2,650	2,055	1,927	2,010
Total revenues	3,983	3,156	3,259	3,551	$ 2,808	$ 2,882	$ 2,488	$ 2,126
Production expenses	463	448	455	457
Exploration expenses	171	57	57	95
Marketing and midstream expenses	2,378	1,824	1,714	1,814
Depreciation, depletion and amortization	528	512	506	528
Asset impairments	8	2		7	81			1,200
Asset dispositions	(18)	(169)	(27)	(3)	(575)	(830)	(75)	(3)
General and administrative expenses	222	203	214	233
Financing costs, net	126	128	116	128
Other expenses	5	(76)	(20)	(33)
Total expenses	3,883	2,929	3,015	3,226
Earnings (loss) before income taxes	100	227	244	325	271	787	(339)	(2,036)
Income tax expense (benefit)	(204)	15	(1)	8
Net earnings (loss)	304	212	245	317
Net earnings attributable to noncontrolling interests	121	19	26	14
Net earnings (loss) attributable to Devon	$ 183	$ 193	$ 219	$ 303	$ 207	$ 613	$ (326)	$ (1,550)
Net earnings per share attributable to Devon:
Basic	$ 0.35	$ 0.37	$ 0.41	$ 0.58	$ 0.41	$ 1.17	$ (0.63)	$ (3.27)
Diluted	$ 0.35	$ 0.37	$ 0.41	$ 0.58	$ 0.41	$ 1.16	$ (0.63)	$ (3.27)
Comprehensive earnings:
Net earnings (loss)	$ 304	$ 212	$ 245	$ 317
Other comprehensive earnings, net of tax:
Foreign currency translation and other	5	42	28	8
Pension and postretirement plans	15	5	4	5
Other comprehensive earnings, net of tax	20	47	32	13
Comprehensive earnings (loss)	324	259	277	330
Comprehensive earnings attributable to noncontrolling interests	121	19	26	14
Comprehensive earnings (loss) attributable to Devon	$ 203	$ 240	$ 251	$ 316

[1] Prior year amounts have been recast due to change in accounting principle. See Note 2 in “Item 8. Financial Statements and Supplementary Data” of this report.