| **Asset Impairments (Details) (USD $)In Millions, unless otherwise specified** | 3 Months Ended | 6 Months Ended |
|--------------------------------------------------------------------------------|----------------|----------------|
||
| **Impairment or Disposal of Tangible Assets Disclosure [Abstract]**            |           |                |   |  |   |  |   |  |
| South Raton (Deepwater Gulf of Mexico)                                         | $ 34           |                | $ 0 |  | $ 34 |  | $ 0 |  |
| Piceance (Onshore US)                                                          | 39             |                | 0 |  | 39 |  | 0 |  |
| East Texas (Onshore US)                                                        | 0              |                | 116 |  | 0 |  | 116 |  |
| Other (Onshore US)                                                             | 0              |                | 15 |  | 0 |  | 21 |  |
| Total Asset Impairment Charges                                                 | $ 73           | [1]            | $ 131 | [1] | $ 73 | [1] | $ 137 | [1] |
|                                                                                |
| [1]See Note 4. Asset Impairments.                                              |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The expense recorded to reduce the net book value of oil and gas assets consisting of proved properties and unproved properties in East Texas (Onshore US) to fair value as the estimate of future cash flows from these properties are less than their net book value.
+ References
No definition available.
+ Details**Name:**nbl_EastTexasOnshoreUs**Namespace Prefix:**nbl_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The expense recorded to reduce the net book value of oil and gas assets consisting of proved properties and unproved properties primarily Onshore US to fair value as the estimate of future cash flows is less than the net book value of these properties.
+ References
No definition available.
+ Details**Name:**nbl_OtherPrimarilyOnshoreUs**Namespace Prefix:**nbl_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Expense recorded to reduce the net book value of oil and gas assets consisting of proved properties at our Piceance (Onshore US) property to fair value as the estimate of future cash flows from this asset is less than its net book value.
+ References
No definition available.
+ Details**Name:**nbl_PiceanceOnshoreUs**Namespace Prefix:**nbl_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Expense recorded to reduce the net book value of oil and gas assets consisting of proved properties at our South Raton (Deepwater Gulf of Mexico) field to fair value as the estimate of future cash flows from this asset is less than its net book value.
+ References
No definition available.
+ Details**Name:**nbl_SouthRatonDeepwaterGulfOfMexico**Namespace Prefix:**nbl_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 19 -Paragraph 27, 28, 29 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 360 -Section 35 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=6475018&loc=d3e66150-109466Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6391110&loc=d3e2921-110230
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| X                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_ImpairmentOrDisposalOfTangibleAssetsDisclosureAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |