| **Finance Receivables - Narrative (Details) (USD $)**                  | Oct. 31, 2014segments                                                                                                                     | Oct. 31, 2013                                                                                                                             |
|------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------|
| **Schedule of Securitization [Line Items]**                            |                                                                                                                                      |                                                                                                                                      |
| Loans and Leases Receivable, Net Amount                                | $ 2,000,000,000us-gaap_LoansAndLeasesReceivableNetReportedAmount                                                                          | $ 1,900,000,000us-gaap_LoansAndLeasesReceivableNetReportedAmount                                                                          |
| Number of Portfolio Segments for Finance Receivables                   | 2nav_NumberofPortfolioSegmentsforFinanceReceivables                                                                                       |                                                                                                                                      |
| Trac Funding Facility [Member]                                         |                                                                                                                                      |                                                                                                                                      |
| **Schedule of Securitization [Line Items]**                            |                                                                                                                                      |                                                                                                                                      |
| Finance Receivables Retail Accounts Collateral For Borrowed Securities | 996,000,000nav_FinanceReceivablesRetailAccountsCollateralForBorrowedSecurities/ us-gaap_DebtInstrumentAxis= nav_TracFundingFacilityMember | 948,000,000nav_FinanceReceivablesRetailAccountsCollateralForBorrowedSecurities/ us-gaap_DebtInstrumentAxis= nav_TracFundingFacilityMember |
| Cash Collateral for Borrowed Securities                                | 93,000,000us-gaap_CashCollateralForBorrowedSecurities/ us-gaap_DebtInstrumentAxis= nav_TracFundingFacilityMember                          | 4,000,000us-gaap_CashCollateralForBorrowedSecurities/ us-gaap_DebtInstrumentAxis= nav_TracFundingFacilityMember                           |
| Financial Services Operations [Member]                                 |                                                                                                                                      |                                                                                                                                      |
| **Schedule of Securitization [Line Items]**                            |                                                                                                                                      |                                                                                                                                      |
| Assets Net Of Intercompany Balances                                    | $ 2,600,000,000nav_AssetsNetOfIntercompanyBalances/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember          | $ 2,400,000,000nav_AssetsNetOfIntercompanyBalances/ us-gaap_StatementBusinessSegmentsAxis= nav_FinancialServicesOperationsMember          |

| X                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Assets Net Of Intercompany Balances
+ References
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| X                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Finance Receivables Retail Accounts Collateral For Borrowed Securities
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of Portfolio Segments for Finance Receivables
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount as of the balance sheet date of cash collateral held for borrowed securities, for which the cash is restricted as to withdrawal or usage.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.1) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.(a),2) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 2 -Article 7
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.
+ References
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| X                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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