| **Financial Instruments and Commodity Contracts - Foreign Currency Contracts (Details) (Foreign Exchange Contract [Member])In Millions, unless otherwise specified** | Oct. 31, 2014USD ($)                                                                                            | Oct. 31, 2014EUR (€)                                                                                            | Oct. 31, 2013EUR (€) | Oct. 31, 2014Contract 1 [Member]USD ($)                                                                                | Oct. 31, 2014Contract 1 [Member]CAD                                                                                                                                        | Oct. 31, 2013Contract 1 [Member]USD ($)                                                                                                                                  | Oct. 31, 2013Contract 1 [Member]CAD                                                                                                                                         | Oct. 31, 2013Contract 2 [Member]CAD                                                                                                                                       |
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| **Derivative [Line Items]**                                                                                                                                          |                                                                                                            |                                                                                                                   |                             |                                                                                                                   |                                                                                                                                                                       |                                                                                                                                                                     |                                                                                                                                                                        |                                                                                                                                                                      |   |
| Derivative, Notional Amount                                                                                                                                          | $ 4invest_DerivativeNotionalAmount/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember | € 9invest_DerivativeNotionalAmount/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember | [1]                         | € 2invest_DerivativeNotionalAmount/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember | $ 4invest_DerivativeNotionalAmount/ nav_DerivativeInstrumentContractAxis= nav_Contract1Member/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember | 5invest_DerivativeNotionalAmount/ nav_DerivativeInstrumentContractAxis= nav_Contract1Member/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember | $ 25invest_DerivativeNotionalAmount/ nav_DerivativeInstrumentContractAxis= nav_Contract1Member/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember | 90invest_DerivativeNotionalAmount/ nav_DerivativeInstrumentContractAxis= nav_Contract1Member/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember | 50invest_DerivativeNotionalAmount/ nav_DerivativeInstrumentContractAxis= nav_Contract2Member/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember |
|                                                                                                                                                                      |
| [1]Forward exchange contracts of €1 expire on the last day of each month from February 2015 through October 2015.                                             |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.
+ 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_DerivativeNotionalAmount**Namespace Prefix:**invest_**Data Type:**xbrli:monetaryItemType**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 |