Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended			9 Months Ended
		Jul. 20, 2015	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Income (Loss) Attributable to Parent			$ (144)	$ (283)		$ (746)	$ (413)
Weighted Average, Number of Shares Outstanding, Basic (in shares)	[1]		430,000,000	420,000,000		430,000,000	392,000,000
Weighted Average, Number of Shares Outstanding, Diluted (in shares)	[2]		430,000,000	420,000,000		430,000,000	392,000,000
Earnings (Loss) from Continuing Operations Per Share, Basic (in dollars per share)			$ (0.33)	$ (0.67)		$ (1.73)	$ (1.05)
Earnings (Loss) from Continuing Operations Per Share, Diluted (in dollars per share)			$ (0.33)	$ (0.67)		$ (1.73)	$ (1.05)
Number of antidilutive stock options, shares of restricted stock and shares of common stock in rabbi trust excluded from calculation above (in shares)			14,000,000	14,000,000		15,000,000	11,000,000
Underwritten public offering (in shares)					24,150,000
Shares exchange in acquisition		41,000,000

[1] 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.

[2] For all periods, all outstanding options and non-vested restricted shares have been excluded from the calculation of diluted loss per share as Noble Energy incurred a net loss. Therefore, inclusion of outstanding options and non-vested restricted shares in the calculation of diluted loss per share would be anti-dilutive.