Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Loss	Treasury Stock at Cost	Retained Earnings	Non- controlling Interests
Balance at Beginning of Period at Dec. 31, 2015	$ 10,370	$ 5	$ 6,360	$ (33)	$ (688)	$ 4,726	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(745)					(746)	1
Stock-based Compensation	57		57
Dividends (30 cents per share)	(129)					(129)
Issuance of Noble Midstream Partners Common Units, Net of Offering Costs	299						299
Other	(7)			1	(8)
Balance at End of Period at Sep. 30, 2016	9,845	5	6,417	(32)	(696)	3,851	300
Balance at Beginning of Period at Dec. 31, 2016	9,600	5	6,450	(31)	(692)	3,556	312
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(1,566)					(1,612)	46
Clayton Williams Energy Acquisition	1,851		1,876		(25)
Stock-based Compensation	80		80
Dividends (30 cents per share)	(141)					(141)
Issuance of Noble Midstream Partners Common Units, Net of Offering Costs	138						138
Distributions to Noncontrolling Interest Owners	(19)						(19)
Other			9	2	(11)
Balance at End of Period at Sep. 30, 2017	$ 9,943	$ 5	$ 8,415	$ (29)	$ (728)	$ 1,803	$ 477