| **Asset Impairments (Tables)**                        | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Asset Impairments [Abstract]**                      |                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Summary of details of impairment of long-lived assets | Pre-tax (non-cash) asset impairment charges were as follows: Three Months Ended September 30, Nine Months EndedSeptember 30,(millions)2015 2014 2015 2014US Properties, Primarily Shelf and Deepwater Gulf of Mexico$— $2 $11 $56Eastern Mediterranean— 31 32 14North Sea— — — 94Total$— $33 $43 $164 |

| X                                                                                                                                                                                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Asset Impairments [Abstract]
+ References
No definition available.
+ Details**Name:**nbl_AssetImpairmentsAbstract**Namespace Prefix:**nbl_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tabular disclosure for impairment of long-lived assets held and used by an entity which includes a description of the impaired long-lived asset and facts and circumstances leading to the impairment, aggregate amount of the impairment loss and where the loss is located in the income statement, method(s) for determining fair value, and the segment in which the impaired long-lived asset is reported.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6391110&loc=d3e2921-110230Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 5 -Section CC -Subsection 3
+ Details**Name:**us-gaap_DetailsOfImpairmentOfLongLivedAssetsHeldAndUsedByAssetTextBlock**Namespace Prefix:**us-gaap_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |