Net Loss Per Share Attributable to Noble Energy Common Shareholders (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net Loss and Comprehensive Loss Attributable to Noble Energy	$ (408)	$ (10)	$ (4,371)	$ (323)
Weighted average number of shares outstanding, basic (in shares)	479	478	480	478
Incremental shares from assumed conversion of dilutive stock options, restricted stock, and shares of common stock in rabbi trust (in shares)	0	0	0	0
Weighted average number of shares outstanding, diluted (in shares)	479	478	480	478
Loss per share, basic and diluted ($ per share)	$ (0.85)	$ (0.02)	$ (9.11)	$ (0.68)
Number of Antidilutive Stock Options, Shares of Restricted Stock, and Shares of Common Stock in Rabbi Trust Excluded from Calculation Above	16	15	16	15