| **Fair Value Measurements and Disclosures of Assets and Liabilities Measured on a Recurring Basis (Details) (USD $)In Millions, unless otherwise specified**                                                                                                                                                 | Dec. 31, 2012 | Dec. 31, 2011 |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Financial Assets [Abstract]**                                                                                                                                                                                                                                                                              |          |               |   |  |
| Mutual Fund Investments                                                                                                                                                                                                                                                                                      | $ 103         |               | $ 99 |  |
| Commodity Derivative Investments                                                                                                                                                                                                                                                                             | 84            |               | 47 |  |
| **Financial Liabilities [Abstract]**                                                                                                                                                                                                                                                                         |          |               |   |  |
| Commodity Derivative Instruments                                                                                                                                                                                                                                                                             | (10)          |               | (83) |  |
| Portion of Deferred Compensation Liability Measured at Fair Value                                                                                                                                                                                                                                            | (160)         |               | (162) |  |
| Quoted Prices in Active Markets (Level 1)                                                                                                                                                                                                                                                                    |          |               |   |  |
| **Financial Assets [Abstract]**                                                                                                                                                                                                                                                                              |          |               |   |  |
| Mutual Fund Investments                                                                                                                                                                                                                                                                                      | 103           | [1]           | 99 | [1] |
| Commodity Derivative Investments                                                                                                                                                                                                                                                                             | 0             | [1]           | 0 | [1] |
| **Financial Liabilities [Abstract]**                                                                                                                                                                                                                                                                         |          |               |   |  |
| Commodity Derivative Instruments                                                                                                                                                                                                                                                                             | 0             | [1]           | 0 | [1] |
| Portion of Deferred Compensation Liability Measured at Fair Value                                                                                                                                                                                                                                            | (160)         | [1]           | (162) | [1] |
| Significant Other Observable Inputs (Level 2)                                                                                                                                                                                                                                                                |          |               |   |  |
| **Financial Assets [Abstract]**                                                                                                                                                                                                                                                                              |          |               |   |  |
| Mutual Fund Investments                                                                                                                                                                                                                                                                                      | 0             | [1]           | 0 | [1] |
| Commodity Derivative Investments                                                                                                                                                                                                                                                                             | 113           | [1]           | 99 | [1] |
| **Financial Liabilities [Abstract]**                                                                                                                                                                                                                                                                         |          |               |   |  |
| Commodity Derivative Instruments                                                                                                                                                                                                                                                                             | (39)          | [1]           | (135) | [1] |
| Portion of Deferred Compensation Liability Measured at Fair Value                                                                                                                                                                                                                                            | 0             | [1]           | 0 | [1] |
| Significant Unobservable Inputs (Level 3)                                                                                                                                                                                                                                                                    |          |               |   |  |
| **Financial Assets [Abstract]**                                                                                                                                                                                                                                                                              |          |               |   |  |
| Mutual Fund Investments                                                                                                                                                                                                                                                                                      | 0             | [1]           | 0 | [1] |
| Commodity Derivative Investments                                                                                                                                                                                                                                                                             | 0             | [1]           | 0 | [1] |
| **Financial Liabilities [Abstract]**                                                                                                                                                                                                                                                                         |          |               |   |  |
| Commodity Derivative Instruments                                                                                                                                                                                                                                                                             | 0             | [1]           | 0 | [1] |
| Portion of Deferred Compensation Liability Measured at Fair Value                                                                                                                                                                                                                                            | 0             | [1]           | 0 | [1] |
| Adjustment                                                                                                                                                                                                                                                                                                   |          |               |   |  |
| **Financial Assets [Abstract]**                                                                                                                                                                                                                                                                              |          |               |   |  |
| Mutual Fund Investments                                                                                                                                                                                                                                                                                      | 0             | [2]           | 0 | [2] |
| Commodity Derivative Investments                                                                                                                                                                                                                                                                             | (29)          | [2]           | (52) | [2] |
| **Financial Liabilities [Abstract]**                                                                                                                                                                                                                                                                         |          |               |   |  |
| Commodity Derivative Instruments                                                                                                                                                                                                                                                                             | 29            | [2]           | 52 | [2] |
| Portion of Deferred Compensation Liability Measured at Fair Value                                                                                                                                                                                                                                            | $ 0           | [2]           | $ 0 | [2] |
|                                                                                                                                                                                                                                                                                                              |
| [1]See Note 1. Summary of Significant Accounting Policies - Fair Value Measurements for a description of the fair value hierarchy.[2]Amount represents the impact of netting clauses within our master agreements that allow us to net cash settle asset and liability positions with the same counterparty. |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents a certain statement of financial position liability caption which represents a commodity derivative liability, measured at fair value on a recurring basis.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents a certain statement of financial position liability caption which represents a deferred compensation liability, measured at fair value on a recurring basis.
+ References
No definition available.
+ Details**Name:**nbl_FairValueLiabilitiesMeasuredOnRecurringBasisDeferredCompensationLiability**Namespace Prefix:**nbl_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**nbl_FinancialAssetsAbstract**Namespace Prefix:**nbl_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**nbl_FinancialLiabilitiesAbstract**Namespace Prefix:**nbl_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investment securities as of the balance sheet date which may include marketable securities, derivative financial instruments, and investments accounted for under the equity method.
+ References
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