Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended	12 Months Ended
		Jul. 20, 2015	Mar. 03, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations					$ (2,441)	$ 1,214	$ 907
Earnings Adjustment from Assumed Conversion of Dilutive Shares of Common Stock in Rabbi Trust	[1]				0	(17)	0
Income (Loss) from Continuing Operations Used for Diluted Earnings (Loss) Per Share Calculation					$ (2,441)	$ 1,197	$ 907
Weighted Average Number of Shares Outstanding, Basic (in shares)					402,000,000	361,000,000	359,000,000
Incremental Shares From Assumed Conversion of Dilutive Stock Options and Restricted Stock (in shares)					0	6,000,000	4,000,000
Weighted Average Number of Shares Outstanding, Diluted (in shares)					402,000,000	367,000,000	363,000,000
Earnings (Loss) from Continuing Operations Per Share, Basic (in dollars per share)					$ (6.07)	$ 3.36	$ 2.53
Earnings (Loss) from Continuing Operations Per Share, Diluted (in dollars per share)					$ (6.07)	$ 3.27	$ 2.50
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)					10,000,000	3,000,000	3,000,000
Weighted average Exercise Price of antidilutive options (in dollars per share)					$ 52.39	$ 60.30	$ 53.40
Shares issued					24,150,000	0
Shares of Noble Energy common stock issued to Rosetta shareholders					41,048,240	0
Underwritten Public Offering
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares issued			21,000,000	24,150,000
Rosetta Resources, Inc
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares of Noble Energy common stock issued to Rosetta shareholders		41,000,000

[1] Consistent with GAAP, when dilutive, deferred compensation gains or losses, net of tax, are excluded from net income while our common shares held in the rabbi trust are included in the diluted share count. For this reason, the diluted earnings (loss) per share calculation for the year ended December 31, 2014 excludes deferred compensation gains, net of tax.(2) The weighted average number of shares outstanding includes the weighted average shares of common stock issued in connection with the underwritten public offering of 24.15 million shares of Noble Energy common stock in first quarter 2015 and issued in connection with the exchange of approximately 41 million shares for all outstanding shares of Rosetta common stock on July 20, 2015.