Income Taxes - Income Tax Provision, Effective Income Tax Reconciliation, and Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of income (loss) before income taxes [Abstract]
Domestic	$ (2,831)	$ (1,859)	$ (2,338)
Foreign	640	87	119
Loss Before Income Taxes	(2,191)	(1,772)	(2,219)
Current Taxes
Federal	(11)	(4)	(1)
State	1	5	0
Foreign	96	196	107
Total Current	86	197	106
Deferred Taxes
Federal	(1,258)	(784)	216
State	(8)	(24)	(5)
Foreign	39	(176)	(95)
Total Deferred	(1,227)	(984)	116
Total Income Tax (Benefit) Provision Attributable to Noble Energy	$ (1,141)	$ (787)	$ 222
Effective Tax Rate (in hundredths)	52.10%	44.40%	(10.00%)
Federal statutory tax rate reconciliation [Abstract]
Federal Statutory Rate (in hundredths)	35.00%	35.00%	35.00%
Effect of
Earnings of Equity Method Investees	1.90%	1.00%	0.60%
Noncontrolling Interests	1.10%	0.40%	(0.00%)
US and Foreign Statutory Rate Change	23.50%	1.60%	0.00%
Transition Tax	(4.80%)	0.00%	0.00%
State Taxes, Net of Federal Benefit	0.30%	1.30%	0.30%
Difference Between US and Foreign Rates	1.80%	(0.10%)	2.60%
Foreign Exploration Loss	0.00%	0.10%	2.70%
Change in Valuation Allowance	(17.40%)	(2.00%)	0.00%
Oil Profits Tax - Israel	(0.10%)	0.00%	0.10%
Tax Contingency	0.10%	0.20%	0.40%
Accumulated Undistributed Foreign Earnings	11.00%	7.20%	(37.70%)
Goodwill Impairment	0.00%	0.00%	(12.30%)
Other, Net	(0.30%)	(0.30%)	(1.70%)
Effective Rate	52.10%	44.40%	(10.00%)
Deferred Tax Assets
Loss Carryforwards	$ 902	$ 474
Employee Compensation and Benefits	97	150
Mark to Market of Commodity Derivative Instruments	7	44
Foreign Tax Credits	366	0
Other	104	49
Total Deferred Tax Assets	1,476	717
Valuation Allowance - Foreign Loss Carryforwards and Foreign Tax Credits	(549)
Net Deferred Tax Assets	927	475
Deferred Tax Liabilities
Accumulated Undistributed Foreign Earnings	0	(240)
Property, Plant and Equipment, Principally Due to Differences in Depreciation, Amortization, Lease Impairment and Abandonments	(2,029)	(2,054)
Total Deferred Tax Liability	(2,029)	(2,294)
Net Deferred Tax Liability	(1,102)	$ (1,819)
Deferred tax benefit, removal of assertion of indefinitely reinvested earnings	$ 240