Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended
		Jul. 20, 2015	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net Loss			$ (287)	$ (22)
Weighted Average, Number of Shares Outstanding, Basic (in shares)	[1]		429,000,000	370,000,000
Weighted Average, Number of Shares Outstanding, Diluted (in shares)			429,000,000	370,000,000
Earnings (Loss) from Continuing Operations Per Share, Basic (in dollars per share)			$ (0.67)	$ (0.06)
Earnings (Loss) from Continuing Operations Per Share, Diluted (in dollars per share)			$ (0.67)	$ (0.06)
Number of antidilutive stock options, shares of restricted stock and shares of common stock in rabbi trust excluded from calculation above (in shares)			15,000,000	9,000,000
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.