| **Derivative Instruments and Hedging Activities (Details) (USD $)In Millions, unless otherwise specified** | 3 Months Ended | 12 Months Ended |        |
|------------------------------------------------------------------------------------------------------------|----------------|-----------------|--------|
||
| **Derivative Instruments and Hedging Activities [Abstract]**                                               |           |            |   |
| Amount of Gain (Loss) on Derivative Instruments Recognized in Other Comprehensive (Income) Loss            | $ 23           |            |   |
| Net liability position of settled interest rate swap                                                       |           |            | 40     |
| AOCL amount, net of tax, to be reclassified to interest expense over life of debt, original amount         |           |            | 26     |
| AOCL amount, net of tax, to be reclassified to interest expense over life of debt                          |           | 24              |   |
| Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months                                        |           | $ 1             |   |
| Crude Oil Commodity Contract [Member] | Swaps - NYMEX WTI 2014                                             |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2014            |   |
| Index                                                                                                      |           | NYMEX WTI       |   |
| Volume Per Day                                                                                             |           | 37,000          |   |
| Weighted Average Fixed Price                                                                               |           | 92.67           |   |
| Weighted Average Short Put Price                                                                           |           |       |   |
| Weighted Average Floor Price                                                                               |           |       |   |
| Weighted Average Ceiling Price                                                                             |           |       |   |
| Crude Oil Commodity Contract [Member] | Swaps - Dated Brent 2014                                           |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2014            |   |
| Index                                                                                                      |           | Dated Brent     |   |
| Volume Per Day                                                                                             |           | 13,000          |   |
| Weighted Average Fixed Price                                                                               |           | 103.21          |   |
| Weighted Average Short Put Price                                                                           |           |       |   |
| Weighted Average Floor Price                                                                               |           |       |   |
| Weighted Average Ceiling Price                                                                             |           |       |   |
| Crude Oil Commodity Contract [Member] | Three Way Collars - NYMEX WTI 2014                                 |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2014            |   |
| Index                                                                                                      |           | NYMEX WTI       |   |
| Volume Per Day                                                                                             |           | 12,000          |   |
| Weighted Average Fixed Price                                                                               |           |       |   |
| Weighted Average Short Put Price                                                                           |           | 75.67           |   |
| Weighted Average Floor Price                                                                               |           | 90.67           |   |
| Weighted Average Ceiling Price                                                                             |           | 100.88          |   |
| Crude Oil Commodity Contract [Member] | Three Way Collars - Dated Brent 2014                               |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2014            |   |
| Index                                                                                                      |           | Dated Brent     |   |
| Volume Per Day                                                                                             |           | 8,000           |   |
| Weighted Average Fixed Price                                                                               |           | 0.00            |   |
| Weighted Average Short Put Price                                                                           |           | 84.38           |   |
| Weighted Average Floor Price                                                                               |           | 98.25           |   |
| Weighted Average Ceiling Price                                                                             |           | 121.56          |   |
| Crude Oil Commodity Contract [Member] | Swaps - NYMEX WTI 2015                                             |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2015            |   |
| Index                                                                                                      |           | NYMEX WTI       |   |
| Volume Per Day                                                                                             |           | 16,000          |   |
| Weighted Average Fixed Price                                                                               |           | 87.66           |   |
| Weighted Average Short Put Price                                                                           |           |       |   |
| Weighted Average Floor Price                                                                               |           |       |   |
| Weighted Average Ceiling Price                                                                             |           |       |   |
| Crude Oil Commodity Contract [Member] | Swaps - Dated Brent 2015                                           |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2015            |   |
| Index                                                                                                      |           | Dated Brent     |   |
| Volume Per Day                                                                                             |           | 8,000           |   |
| Weighted Average Fixed Price                                                                               |           | 100.20          |   |
| Weighted Average Short Put Price                                                                           |           |       |   |
| Weighted Average Floor Price                                                                               |           |       |   |
| Weighted Average Ceiling Price                                                                             |           |       |   |
| Crude Oil Commodity Contract [Member] | Three Way Collars - NYMEX WTI 2015                                 |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2015            |   |
| Index                                                                                                      |           | NYMEX WTI       |   |
| Volume Per Day                                                                                             |           | 15,000          |   |
| Weighted Average Fixed Price                                                                               |           |       |   |
| Weighted Average Short Put Price                                                                           |           | 70.67           |   |
| Weighted Average Floor Price                                                                               |           | 88.00           |   |
| Weighted Average Ceiling Price                                                                             |           | 94.78           |   |
| Crude Oil Commodity Contract [Member] | Three Way Collars - Dated Brent 2015                               |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2015            |   |
| Index                                                                                                      |           | Dated Brent     |   |
| Volume Per Day                                                                                             |           | 11,000          |   |
| Weighted Average Fixed Price                                                                               |           |       |   |
| Weighted Average Short Put Price                                                                           |           | 76.36           |   |
| Weighted Average Floor Price                                                                               |           | 95.27           |   |
| Weighted Average Ceiling Price                                                                             |           | 109.26          |   |
| Natural Gas Commodity Contract [Member] | Swaps - NYMEX HH 2014                                            |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2014            |   |
| Index                                                                                                      |           | NYMEX HH        |   |
| Volume Per Day                                                                                             |           | 60,000          |   |
| Weighted Average Fixed Price                                                                               |           | 4.24            |   |
| Weighted Average Short Put Price                                                                           |           |       |   |
| Weighted Average Floor Price                                                                               |           |       |   |
| Weighted Average Ceiling Price                                                                             |           |       |   |
| Natural Gas Commodity Contract [Member] | Three Way Collars NYMEX HH 2014                                  |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2014            |   |
| Index                                                                                                      |           | NYMEX HH        |   |
| Volume Per Day                                                                                             |           | 230,000         |   |
| Weighted Average Fixed Price                                                                               |           |       |   |
| Weighted Average Short Put Price                                                                           |           | 2.83            |   |
| Weighted Average Floor Price                                                                               |           | 3.75            |   |
| Weighted Average Ceiling Price                                                                             |           | 4.98            |   |
| Natural Gas Commodity Contract [Member] | Swaps NYMEX HH 2015                                              |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2015            |   |
| Index                                                                                                      |           | NYMEX HH        |   |
| Volume Per Day                                                                                             |           | 80,000          |   |
| Weighted Average Fixed Price                                                                               |           | 4.32            |   |
| Weighted Average Short Put Price                                                                           |           |       |   |
| Weighted Average Floor Price                                                                               |           |       |   |
| Weighted Average Ceiling Price                                                                             |           |       |   |
| Natural Gas Commodity Contract [Member] | Three Way Collars NYMEX HH 2015                                  |           |            |   |
| **Derivative [Line Items]**                                                                                |           |            |   |
| Settlement Period                                                                                          |           | 2015            |   |
| Index                                                                                                      |           | NYMEX HH        |   |
| Volume Per Day                                                                                             |           | 120,000         |   |
| Weighted Average Fixed Price                                                                               |           |       |   |
| Weighted Average Short Put Price                                                                           |           | 3.54            |   |
| Weighted Average Floor Price                                                                               |           | 4.25            |   |
| Weighted Average Ceiling Price                                                                             |           | 5.06            |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B
+ Details**Name:**invest_DerivativeNonmonetaryNotionalAmount**Namespace Prefix:**invest_**Data Type:**xbrli:decimalItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of gain (loss), net of tax, on derivative instruments recognized in other comprehensive (income) loss prior to settlement of interest rate swap.
+ References
No definition available.
+ Details**Name:**nbl_AmountOfGainLossOnDerivativeInstrumentsRecognizedInOtherComprehensiveIncomeLoss**Namespace Prefix:**nbl_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Net of tax amount remaining in Accumulated Other Comprehensive Loss that will be reclassified into interest expense over the life of the debt.
+ References
No definition available.
+ Details**Name:**nbl_AoclAmountNetOfTaxToBeReclassifiedToInterestExpenseOverLifeOfDebt**Namespace Prefix:**nbl_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Net of tax amount in Accumulated Other Comprehensive Loss that will be reclassified into interest expense over the life of the debt (original amount).
+ References
No definition available.
+ Details**Name:**nbl_AoclAmountNetOfTaxToBeReclassifiedToInterestExpenseOverLifeOfDebtOriginalAmount**Namespace Prefix:**nbl_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**nbl_DerivativeInstrumentsAndHedgingActivitiesAbstract**Namespace Prefix:**nbl_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Contract period of time relating to a derivative instrument.
+ References
No definition available.
+ Details**Name:**nbl_DerivativeProductionPeriod**Namespace Prefix:**nbl_**Data Type:**us-types:dateStringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The position of the settled interest rate swap as of the settlement date.
+ References
No definition available.
+ Details**Name:**nbl_NetLiabilityPositionOfSettledInterestRateSwap**Namespace Prefix:**nbl_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=7668309&loc=d3e80748-113994
+ Details**Name:**us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The average cap rate on a group of price risk derivatives such as caps or collars. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract.
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeAverageCapPrice**Namespace Prefix:**us-gaap_**Data Type:**us-types:perUnitItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                             |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The average floor rate on a group of price risk derivatives such as floors or collars. A payment or receipt is triggered if the market rate falls below the floor rate on the contract.
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeAverageFloorPrice**Namespace Prefix:**us-gaap_**Data Type:**us-types:perUnitItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The average strike price on the group of price risk option contracts such as put options or call options.
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeAveragePriceRiskOptionStrikePrice**Namespace Prefix:**us-gaap_**Data Type:**us-types:perUnitItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_DerivativeLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Average fixed price related to the group of price risk swap derivatives.
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeSwapTypeAverageFixedPrice**Namespace Prefix:**us-gaap_**Data Type:**us-types:perUnitItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Reference to the index or unit of measurement for the underlying which establishes the pricing terms of the derivative instrument. For example, the basis on the underlying for a natural gas futures contract might be the NYMEX price per million British thermal units (MMBtu).
+ References
No definition available.
+ Details**Name:**us-gaap_DerivativeUnderlyingBasis**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |