Debt - Summary of Debt (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Finance Lease Obligations	$ 206
Total Debt	7,551	$ 6,675
Net Unamortized Discounts and Debt Issuance Costs	(57)	(60)
Total Debt	7,494	6,615
Commercial Paper Borrowings	(511)	0
Finance Lease Obligations	(42)	(41)
Long-Term Debt Due After One Year	6,941	6,574
Noble Midstream Services Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	800
Available borrowing capacity	$ 750	$ 740
Senior Notes and Debentures
Debt Instrument [Line Items]
Weighted average interest rate	5.00%	5.01%
Noble Energy
Debt Instrument [Line Items]
Finance Lease Obligations	$ 206	$ 223
Finance Lease Obligations, Interest Rate	0.00%	0.00%
Total Debt	$ 6,601	$ 6,115
Noble Energy | Revolving Credit Facility, due March 9, 2023
Debt Instrument [Line Items]
Debt	$ 0	$ 0
Interest Rate	0.00%	0.00%
Noble Energy | Commercial Paper
Debt Instrument [Line Items]
Debt	$ 511	$ 0
Weighted average interest rate, commercial paper	2.63%
Noble Energy | Senior Notes and Debentures
Debt Instrument [Line Items]
Debt	$ 5,884	5,892
Noble Midstream Partners
Debt Instrument [Line Items]
Total Debt	950	560
Noble Midstream Partners | Revolving Credit Facility | Noble Midstream Services Revolving Credit Facility, due March 9, 2023
Debt Instrument [Line Items]
Debt	$ 50	$ 60
Interest Rate	3.45%	3.67%
Noble Midstream Partners | Revolving Credit Facility | Noble Midstream Services Term Loan Credit Facility, due July 31, 2021
Debt Instrument [Line Items]
Debt	$ 500	$ 500
Interest Rate	3.17%	3.42%
Noble Midstream Partners | Revolving Credit Facility | Noble Midstream Services Term Loan Credit Facility, due August 23, 2022
Debt Instrument [Line Items]
Debt	$ 400
Interest Rate	3.05%	0.00%