Other Comprehensive Earnings (Components Of Other Comprehensive Earnings) (Parenthetical) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Accumulated Other Comprehensive Income Loss [Line Items]
Effect of new accounting pronouncement	$ (33)	[1]
ASU 2018-02 [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Effect of new accounting pronouncement	$ (33)

[1] As a result of Devon’s early adoption of ASU 2018-02 in the fourth quarter of 2018, Devon reclassified $33 million from accumulated other comprehensive income to retained earnings in the December 31, 2018 consolidated balance sheet.