|**Debt (Tables)**                                                         | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
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|**Debt Disclosure [Abstract]**                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
|Schedule of Debt                                                          | Debt consists of the following:March 31, 2020December 31, 2019(millions, except percentages)DebtInterest RateDebtInterest RateNoble Energy, Excluding Noble Midstream PartnersRevolving Credit Facility, due March 9, 2023$1,0001.92%$——%Senior Notes and Debentures5,884(1)5,884(1)Finance Lease Obligations203—%205—%Total Noble Energy Debt, Excluding Noble Midstream Partners Debt7,0876,089Noble Midstream PartnersNoble Midstream Services Revolving Credit Facility, due March 9, 20237502.16%5953.11%Noble Midstream Services Term Loan Credit Facility, due July 31, 20215001.94%5002.85%Noble Midstream Services Term Loan Credit Facility, due August 23, 20224001.82%4002.74%Total Noble Midstream Partners Debt1,6501,495Total Debt8,7377,584Net Unamortized Discounts and Debt Issuance Costs(64)(65)Total Debt, Net of Unamortized Discounts and Debt Issuance Costs8,6737,519Less Amounts Due Within One YearFinance Lease Obligations(41)(42)Long-Term Debt Due After One Year$8,632$7,477(1)The Senior Notes and Debentures have weighted average interest rates of4.93%for bothMarch 31, 2020andDecember 31, 2019.
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|                                                                          | March 31, 2020                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|(millions, except percentages)                                            | Debt                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
|Noble Energy, Excluding Noble Midstream Partners                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
|Revolving Credit Facility, due March 9, 2023                              | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
|Senior Notes and Debentures                                               | 5,884                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Finance Lease Obligations                                                 | 203                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Total Noble Energy Debt, Excluding Noble Midstream Partners Debt          | 7,087                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Noble Midstream Partners                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
|Noble Midstream Services Revolving Credit Facility, due March 9, 2023     | 750                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Noble Midstream Services Term Loan Credit Facility, due July 31, 2021     | 500                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Noble Midstream Services Term Loan Credit Facility, due August 23, 2022   | 400                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Total Noble Midstream Partners Debt                                       | 1,650                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Total Debt                                                                | 8,737                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Net Unamortized Discounts and Debt Issuance Costs                         | (64                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Total Debt, Net of Unamortized Discounts and Debt Issuance Costs          | 8,673                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Less Amounts Due Within One Year                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
|Finance Lease Obligations                                                 | (41                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|Long-Term Debt Due After One Year                                         | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
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|(1)                                                                       | The Senior Notes and Debentures have weighted average interest rates of4.93%for bothMarch 31, 2020andDecember 31, 2019.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Schedule of Carrying Values and Estimated Fair Values of Debt Instruments | Fair value information regarding our debt, which excludes finance lease obligations, is as follows:March 31, 2020December 31, 2019(millions)Carrying AmountFair Value(1)Carrying AmountFair ValueDebt$8,534$6,705$7,379$8,033(1)As ofMarch 31, 2020, the difference between the carrying amount and the fair value is primarily due to increased spreads resulting from thecurrent commodity price, supply and demand environment coupled with the COVID-19 pandemic.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|                                                                          | March 31, 2020                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|(millions)                                                                | Carrying Amount                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
|Debt                                                                      | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     

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