Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Loss	Treasury Stock at Cost	Retained Earnings	Non-controlling Interests
Beginning Balance at Dec. 31, 2015	$ 10,370	$ 5	$ 6,360	$ (33)	$ (688)	$ 4,726	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(985)					(998)	13
Stock-based Compensation	68		68
Exercise of Stock Options	24		24
Dividends	(172)					(172)
Issuance of Noble Midstream Partners Common Units, Net of Offering Costs	299		0				299
Other	(4)		(2)	2	(4)
Ending Balance at Dec. 31, 2016	9,600	5	6,450	(31)	(692)	3,556	312
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(1,050)					(1,118)	68
Clayton Williams Energy Acquisition	1,851		1,876		(25)
Stock-based Compensation	100		100
Exercise of Stock Options	10		10
Dividends	(190)					(190)
Issuance of Noble Midstream Partners Common Units, Net of Offering Costs	312						312
Distributions to Noncontrolling Interest Owners	(28)						(28)
Other	14		2	1	(8)		19
Ending Balance at Dec. 31, 2017	10,619	5	8,438	(30)	(725)	2,248	683
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	14					(66)	80
Stock-based Compensation	78		78
Dividends	(208)					(208)
Purchase and Retirement of Common Stock	(295)		(295)
Clayton Williams Energy Acquisition	(25)		(25)
Contributions from Noncontrolling Interest Owners	353						353
Distributions to Noncontrolling Interest Owners	(51)						(51)
Other	(1)		7	(2)	(5)	6	(7)
Ending Balance at Dec. 31, 2018	$ 10,484	$ 5	$ 8,203	$ (32)	$ (730)	$ 1,980	$ 1,058