Changes in Accounting Principle - Consolidated Statement of Earnings (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		Dec. 31, 2015
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Exploration expenses									$ 380	$ 215	[1]	$ 451	[1]
Depreciation, depletion and amortization									2,074	2,096	[1]	4,022	[1]
Asset impairments									17	1,310	[1]	17,647	[1]
Asset dispositions									(217)	(1,483)	[1]	7	[1]
General and administrative expenses									872	865	[1]	1,193	[1]
Financing costs, net									498	907	[1]	519	[1]
Other expenses									(124)	375	[1]	264	[1]
Earnings (loss) before income taxes									896	(1,317)	[1]	(19,858)	[1]
Income tax expense (benefit)									(182)	141	[1]	(6,213)	[1]
Net earnings (loss)									1,078	(1,458)	[1]	(13,645)	[1]
Net earnings (loss) attributable to Devon									$ 898	$ (1,056)	[1]	$ (12,896)	[1]
Net earnings (loss) per share attributable to Devon:
Basic									$ 1.71	$ (2.09)	[1]	$ (31.72)	[1]
Diluted									$ 1.70	$ (2.09)	[1]	$ (31.72)	[1]
Comprehensive earnings (loss):
Foreign currency translation and other									$ 83	$ 11	[1]	$ (443)	[1]
Comprehensive earnings (loss)									1,190	(1,425)	[1]	(14,078)	[1]
Comprehensive earnings (loss) attributable to Devon									1,010	(1,023)	[1]	(13,329)	[1]
Under Full Cost [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Depreciation, depletion and amortization	$ 417
Asset dispositions	1
General and administrative expenses	174
Financing costs, net	124
Other expenses	15
Earnings (loss) before income taxes	403	$ 272	$ 458	$ 598	$ 375	$ 1,178	$ (1,745)	$ (3,685)	1,731	(3,877)
Income tax expense (benefit)	(191)
Net earnings (loss)	594
Net earnings (loss) attributable to Devon	$ 473	$ 228	$ 425	$ 565	$ 331	$ 993	$ (1,570)	$ (3,056)	$ 1,691	$ (3,302)
Net earnings (loss) per share attributable to Devon:
Basic	$ 0.90	$ 0.43	$ 0.81	$ 1.08	$ 0.63	$ 1.90	$ (3.04)	$ (6.44)	$ 3.22	$ (6.52)
Diluted	$ 0.89	$ 0.43	$ 0.80	$ 1.07	$ 0.63	$ 1.89	$ (3.04)	$ (6.44)	$ 3.20	$ (6.52)
Comprehensive earnings (loss):
Foreign currency translation and other	$ 6
Comprehensive earnings (loss)	615
Comprehensive earnings (loss) attributable to Devon	494
Under Full Cost [Member] | Change from Full Cost Method to Successful Efforts Method [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Depreciation, depletion and amortization									$ 1,579	$ 1,792		3,129
Asset impairments										4,975		20,820
Asset dispositions									(5)	(1,887)
General and administrative expenses									682	658		868
Financing costs, net									494	904		517
Other expenses									(102)	403		179
Earnings (loss) before income taxes									1,731	(3,877)		(21,268)
Income tax expense (benefit)									(140)	(173)		(6,065)
Net earnings (loss)									1,871	(3,704)		(15,203)
Net earnings (loss) attributable to Devon									$ 1,691	$ (3,302)		$ (14,454)
Net earnings (loss) per share attributable to Devon:
Basic									$ 3.22	$ (6.52)		$ (35.55)
Diluted									$ 3.20	$ (6.52)		$ (35.55)
Comprehensive earnings (loss):
Foreign currency translation and other									$ 4	$ 32		$ (559)
Comprehensive earnings (loss)									1,904	(3,650)		(15,752)
Comprehensive earnings (loss) attributable to Devon									1,724	(3,248)		(15,003)
Changes [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Exploration expenses	171
Depreciation, depletion and amortization	111
Asset dispositions	(19)
General and administrative expenses	48
Financing costs, net	2
Other expenses	(10)
Earnings (loss) before income taxes	(303)
Income tax expense (benefit)	(13)
Net earnings (loss)	(290)
Net earnings (loss) attributable to Devon	$ (290)
Net earnings (loss) per share attributable to Devon:
Basic	$ (0.55)
Diluted	$ (0.54)
Comprehensive earnings (loss):
Foreign currency translation and other	$ (1)
Comprehensive earnings (loss)	(291)
Comprehensive earnings (loss) attributable to Devon	$ (291)
Changes [Member] | Change from Full Cost Method to Successful Efforts Method [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Exploration expenses									380	215		451
Depreciation, depletion and amortization									495	304		893
Asset impairments										(3,665)		(3,173)
Asset dispositions									(212)	404		7
General and administrative expenses									190	207		325
Financing costs, net									4	3		2
Other expenses									(22)	(28)		85
Earnings (loss) before income taxes									(835)	2,560		1,410
Income tax expense (benefit)									(42)	314		(148)
Net earnings (loss)									(793)	2,246		1,558
Net earnings (loss) attributable to Devon									$ (793)	$ 2,246		$ 1,558
Net earnings (loss) per share attributable to Devon:
Basic									$ (1.51)	$ 4.43		$ 3.83
Diluted									$ (1.50)	$ 4.43		$ 3.83
Comprehensive earnings (loss):
Foreign currency translation and other									$ 79	$ (21)		$ 116
Comprehensive earnings (loss)									(714)	2,225		1,674
Comprehensive earnings (loss) attributable to Devon									$ (714)	$ 2,225		$ 1,674

[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.