|**Divestitures (Tables)**                                                                 | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                 
|----------------------------------------------------------------------------------------- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**Divestitures [Abstract]**                                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                
|Discontinued Operations Balance Sheet and Income Statement Disclosures [Table Text Block] | Summarized results of discontinued operations are as follows:Three Months EndedMarch 31,(millions)2013Oil and Gas Sales$10Income Before Income Taxes(1)Income Tax Expense7Operating Income (Loss), Net of Tax(8)Gain on Sale, Net of Tax37Discontinued Operations, Net of Tax$29                                                                                                                                                               
|                                                                                         
|                                                                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                
|                                                                                          | Three Months EndedMarch 31,                                                                                                                                                                                                                                                                                                                                                                                                                    
|(millions)                                                                                | 2013                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Oil and Gas Sales                                                                         | $                                                                                                                                                                                                                                                                                                                                                                                                                                              
|Income Before Income Taxes                                                                | (1                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Income Tax Expense                                                                        | 7                                                                                                                                                                                                                                                                                                                                                                                                                                              
|Operating Income (Loss), Net of Tax                                                       | (8                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Gain on Sale, Net of Tax                                                                  | 37                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Discontinued Operations, Net of Tax                                                       | $                                                                                                                                                                                                                                                                                                                                                                                                                                              
|Schedule of Disposal Groups, Gain on Asset Onshore Divestitures [Table Text Block]        | Onshore US PropertiesDuring the first three months of2014, we sold certain non-core onshore US crude oil and natural gas properties. The information regarding the assets sold is as follows:Three Months EndedMarch 31,(millions)2014Sales Proceeds$92LessNet Book Value of Assets Sold(106)Goodwill Allocated to Assets Sold(6)Asset Retirement Obligations Associated with Assets Sold20Other Closing Adjustments(1)Loss on Divestitures$(1)
|                                                                                         
|                                                                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                
|                                                                                          | Three Months EndedMarch 31,                                                                                                                                                                                                                                                                                                                                                                                                                    
|(millions)                                                                                | 2014                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Sales Proceeds                                                                            | $                                                                                                                                                                                                                                                                                                                                                                                                                                              
|Less                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                
|Net Book Value of Assets Sold                                                             | (106                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Goodwill Allocated to Assets Sold                                                         | (6                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Asset Retirement Obligations Associated with Assets Sold                                  | 20                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Other Closing Adjustments                                                                 | (1                                                                                                                                                                                                                                                                                                                                                                                                                                             
|Loss on Divestitures                                                                      | $                                                                                                                                                                                                                                                                                                                                                                                                                                              

X- Details**Name:**
                    nbl_DivestituresAbstract**Namespace Prefix:**
                    nbl_**Data Type:**
                    xbrli:stringItemType**Balance Type:**
                    na**Period Type:**
                    duration X- DefinitionTabular disclosure of disposal groups, which may include the gain (loss) recognized in the income statement and the income statement caption that includes that gain (loss), the classification and carrying value of the assets and liabilities comprising the disposal group, and the segment in which the disposal group was reported.+ ReferencesNo definition available.+ Details**Name:**
                    nbl_ScheduleofDisposalGroupsGainonAssetSaleonshoreUSTableTextBlock**Namespace Prefix:**
                    nbl_**Data Type:**
                    nonnum:textBlockItemType**Balance Type:**
                    na**Period Type:**
                    duration X- DefinitionTabular disclosure of disposal groups, which may include the gain (loss) recognized in the income statement and the income statement caption that includes that gain (loss), amounts of revenues and pretax profit or loss reported in discontinued operations, the classification and carrying value of the assets and liabilities comprising the disposal group, and the segment in which the disposal group was reported. Also may include the amount of adjustments to amounts previously reported in discontinued operations such as resolution of contingencies arising from the disposal transaction or the operations of the component prior to disposal.+ ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1361-107760Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6892542&loc=d3e957-107759Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1510-107760Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2443-110228Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1474-107760+ Details**Name:**
                    us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock**Namespace Prefix:**
                    us-gaap_**Data Type:**
                    nonnum:textBlockItemType**Balance Type:**
                    na**Period Type:**
                    duration