Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows From Operating Activities
Net Loss Including Noncontrolling Interests	$ (1,050)	$ (985)	$ (2,441)
Adjustments to Reconcile Net Loss to Net Cash Provided by Operating Activities
Depreciation, Depletion and Amortization	2,053	2,454	2,131
Asset Impairments	70	92	533
Loss on Marcellus Shale Upstream Divestiture	2,379	0	0
Goodwill Impairment	0	0	779
Dry Hole Cost	9	579	266
Deferred Income Taxes	(1,227)	(984)	116
(Gain) Loss on Commodity Derivative Instruments	(63)	139	(501)
Net Cash Received in Settlement of Commodity Derivative Instruments	13	569	1,009
Gain on Divestitures	(326)	(238)	0
Stock Based Compensation	104	77	86
Non-cash Pension Plan Termination Expense	0	0	82
Loss (Gain) on Debt Extinguishment	98	(80)	0
Undeveloped Leasehold Impairment	62	93	21
Expiration and Amortization of Undeveloped Leaseholds	0	55	92
Other Adjustments for Noncash Items Included in Income	(21)	40	18
Changes in Operating Assets and Liabilities, Net of Assets Acquired and Liabilities Assumed
(Increase) Decrease in Accounts Receivable	(171)	(164)	453
Increase (Decrease) in Accounts Payable	248	(111)	(364)
(Decrease) Increase in Current Income Taxes Payable	(36)	(32)	(94)
(Decrease) Increase in Other Current Liabilities	(101)	(63)	(70)
Other Operating Assets and Liabilities, Net	(90)	(90)	(54)
Net Cash Provided by Operating Activities	1,951	1,351	2,062
Cash Flows From Investing Activities
Additions to Property, Plant and Equipment	(2,649)	(1,541)	(2,979)
Proceeds from Divestitures	2,073	1,241	151
Clayton Williams Energy Acquisition, Net of Cash Received	(616)	0	0
Other Acquisitions	(327)	0	0
Marcellus Shale Acreage Exchange Consideration	0	(213)	0
Other	(87)	82	(43)
Net Cash Used in Investing Activities	(1,606)	(431)	(2,871)
Cash Flows From Financing Activities
Dividends Paid, Common Stock	(190)	(172)	(291)
Proceeds from Issuance of Noble Energy Common Stock, Net of Offering Costs	0	0	1,112
Proceeds from Revolving Credit Facility	1,585	0	0
Repayment of Revolving Credit Facility	(1,355)	0	(70)
Repayment of Clayton Williams Energy Long-term Debt	(595)	0	0
Proceeds from Term Loan Facility	0	1,400	0
Repayment of Term Loan Facility	(550)	(850)	0
Proceeds from Issuance of Senior Notes, Net	1,086	0	0
Repayment of Senior Notes	(1,114)	(1,383)	(12)
Proceeds from Noble Midstream Services Revolving Credit Facility	325	0	0
Repayment of Noble Midstream Services Revolving Credit Facility	(240)	0	0
Proceeds from Issuance of Noble Midstream Partners Common Units, Net of Offering Costs	312	299	0
Other	(114)	(62)	(85)
Net Cash (Used in) Provided By Financing Activities	(850)	(768)	654
(Decrease) Increase in Cash and Cash Equivalents	(505)	152	(155)
Cash and Cash Equivalents at Beginning of Period	1,180	1,028	1,183
Cash and Cash Equivalents at End of Period	$ 675	$ 1,180	$ 1,028