Noncontrolling Interests (Narrative) (Details) - USD ($) shares in Thousands, $ in Millions		1 Months Ended		3 Months Ended	12 Months Ended
		Sep. 30, 2017	Oct. 31, 2015	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Noncontrolling Interest [Line Items]
Net proceeds of common units sold					$ 501	$ 892	[1]	$ 25	[1]
Sale of subsidiary units	[1]							654
Distributions to unitholders other than Devon					354	304	[1]	$ 254	[1]
EnLink [Member]
Noncontrolling Interest [Line Items]
Number of units sold to public for interests in EnLink								26,200
Sale of subsidiary units								$ 654
Preferred units issued		400		400
Net proceeds of preferred units sold		$ 394
EnLink [Member] | General Partner [Member]
Noncontrolling Interest [Line Items]
Common units issued in private placement			2,800
Proceeds of private placement transaction			$ 50
EnLink [Member] | Equity Distribution Agreements [Member]
Noncontrolling Interest [Line Items]
Net proceeds of common units sold					$ 107	$ 167		$ 25
Number of units sold to public for interests in EnLink					6,200	10,000		1,300
EnLink [Member] | Equity Distribution Agreements [Member] | Maximum [Member]
Noncontrolling Interest [Line Items]
Net proceeds of common units sold				$ 600
General Partner And EnLink [Member]
Noncontrolling Interest [Line Items]
Distributions to unitholders other than Devon					$ 354	$ 304		$ 254

[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.