| **Summary of Significant Accounting Policies (Details 2) (USD $)**         | Dec. 31, 2014                                     | Dec. 31, 2013                                     | Apr. 24, 2012                                                                                           |
|----------------------------------------------------------------------------|---------------------------------------------------|---------------------------------------------------|---------------------------------------------------------------------------------------------------------|
| **Change in Stockholder Equity Due to Shareholder Amendment [Line Items]** |                                              |                                              |                                                                                                    |
| Common Stock, shares authorized (in shares)                                | 500,000,000us-gaap_CommonStockSharesAuthorized    | 500,000,000us-gaap_CommonStockSharesAuthorized    | 250,000,000us-gaap_CommonStockSharesAuthorized                                                          |
| Common Stock, par value per share (in dollars per share)                   | $ 0.01us-gaap_CommonStockParOrStatedValuePerShare | $ 0.01us-gaap_CommonStockParOrStatedValuePerShare | $ 3.33us-gaap_CommonStockParOrStatedValuePerShare                                                       |
| Shareholder Amendment [Member]                                             |                                              |                                              |                                                                                                    |
| **Change in Stockholder Equity Due to Shareholder Amendment [Line Items]** |                                              |                                              |                                                                                                    |
| Common Stock, shares authorized (in shares)                                |                                              |                                              | 500,000,000us-gaap_CommonStockSharesAuthorized/ us-gaap_PlanNameAxis= nbl_ShareholderAmendmentMember    |
| Common Stock, par value per share (in dollars per share)                   |                                              |                                              | $ 0.01us-gaap_CommonStockParOrStatedValuePerShare/ us-gaap_PlanNameAxis= nbl_ShareholderAmendmentMember |

| X                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Face amount or stated value per share of common stock.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The maximum number of common shares permitted to be issued by an entity's charter and bylaws.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5
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| X                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------|
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