|**Additional Shareholders' Equity Information (Tables)**                                                    | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|----------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**Additional Shareholders' Equity Information [Abstract]**                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Schedule Of Activity In Shares Of Common And Treasury Stock                                                 | Activity in shares of our common stock and treasury stock was as follows:Year Ended December 31,20162015Common Stock Shares IssuedShares, Beginning of Period469,718,512402,329,325Exercise of Common Stock Options954,898343,145Restricted Stock Awards, Net of Forfeitures687,0171,847,802Public Equity Offering—24,150,000Shares Exchanged in Rosetta Merger—41,048,240Shares, End of Period471,360,427469,718,512Treasury StockShares, Beginning of Period37,925,62537,635,890Shares Received From Employees in Payment of Withholding Taxes Due on Vesting of Shares of Restricted Stock236,700490,744Rabbi Trust Shares Distributed and/or Sold(201,009)(201,009)Shares, End of Period37,961,31637,925,625
|                                                                                                           
|                                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|                                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|                                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Common Stock Shares Issued                                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Shares, Beginning of Period                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Exercise of Common Stock Options                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Restricted Stock Awards, Net of Forfeitures                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Public Equity Offering                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Shares Exchanged in Rosetta Merger                                                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Shares, End of Period                                                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Treasury Stock                                                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Shares, Beginning of Period                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Shares Received From Employees in Payment of Withholding Taxes Due on Vesting of Shares of Restricted Stock |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Rabbi Trust Shares Distributed and/or Sold                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Shares, End of Period                                                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Accumulated other comprehensive income (loss) in the shareholders' equity section of the balance sheet      | Accumulated other comprehensive loss in the shareholders’ equity section of the balance sheet included:Accumulated Other Comprehensive Loss(millions)Interest RateCash FlowHedgesPension-Related andOtherTotalDecember 31, 2013$(24)$(93)$(117)Realized Amounts Reclassified Into Earnings11112Unrealized Change in Fair Value—1515December 31, 2014(23)(67)(90)Realized Amounts Reclassified Into Earnings16263Unrealized Change in Fair Value—(6)(6)December 31, 2015(22)(11)(33)Realized Amounts Reclassified Into Earnings145Unrealized Change in Fair Value—(3)(3)December 31, 2016$(21)$(10)$(31)                                                                                                         
|                                                                                                           
|                                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|                                                                                                            | Accumulated Other Comprehensive Loss                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|(millions)                                                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|December 31, 2013                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Realized Amounts Reclassified Into Earnings                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Unrealized Change in Fair Value                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|December 31, 2014                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Realized Amounts Reclassified Into Earnings                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Unrealized Change in Fair Value                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|December 31, 2015                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Realized Amounts Reclassified Into Earnings                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Unrealized Change in Fair Value                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|December 31, 2016                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 

X- ReferencesNo definition available.
+ Details**Name:**
nbl_AdditionalShareholdersEquityInformationAbstract**Namespace Prefix:**
nbl_**Data Type:**
xbrli:stringItemType**Balance Type:**
na**Period Type:**
duration X- DefinitionThis element may be used to capture the reconciliation of shares of common and treasury stock from the beginning of a period to the end of a period.
+ ReferencesNo definition available.
+ Details**Name:**
nbl_ScheduleOfActivityInSharesOfCommonAndTreasuryStockTableTextBlock**Namespace Prefix:**
nbl_**Data Type:**
nonnum:textBlockItemType**Balance Type:**
na**Period Type:**
duration X- DefinitionTabular disclosure of the components of accumulated other comprehensive income (loss).
+ ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669686-108580
+ Details**Name:**
us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock**Namespace Prefix:**
us-gaap_**Data Type:**
nonnum:textBlockItemType**Balance Type:**
na**Period Type:**
duration