| **Finance Receivables - Narrative (Details) $ in Millions**            | Jul. 31, 2016 USD ($) segments | Oct. 31, 2015 USD ($) |
|------------------------------------------------------------------------|--------------------------------|-----------------------|
| **Schedule of Securitization [Line Items]**                            |                           |                  |
| Loans and Leases Receivable, Net Amount                                | $ 1,600                        | $ 2,000               |
| Number of Portfolio Segments for Finance Receivables | segments        | 2                              |                  |
| Trac Funding Facility [Member]                                         |                           |                  |
| **Schedule of Securitization [Line Items]**                            |                           |                  |
| Finance Receivables Retail Accounts Collateral For Borrowed Securities | $ 917                          | 1,000                 |
| Cash Collateral for Borrowed Securities                                | 54                             | 96                    |
| Financial Services Operations [Member]                                 |                           |                  |
| **Schedule of Securitization [Line Items]**                            |                           |                  |
| Assets Net Of Intercompany Balances                                    | $ 2,100                        | $ 2,500               |

| X                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Assets Net Of Intercompany Balances
+ References
No definition available.
+ Details**Name:**nav_AssetsNetOfIntercompanyBalances**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Finance Receivables Retail Accounts Collateral For Borrowed Securities
+ References
No definition available.
+ Details**Name:**nav_FinanceReceivablesRetailAccountsCollateralForBorrowedSecurities**Namespace Prefix:**nav_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of Portfolio Segments for Finance Receivables
+ References
No definition available.
+ Details**Name:**nav_NumberofPortfolioSegmentsforFinanceReceivables**Namespace Prefix:**nav_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**instant |
| 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=d3e572229-122910
+ Details**Name:**us-gaap_CashCollateralForBorrowedSecurities**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| 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
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878
+ Details**Name:**us-gaap_LoansAndLeasesReceivableNetReportedAmount**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
+ Details**Name:**us-gaap_SecuritizationFinancialAssetForWhichTransferIsAccountedAsSaleLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_DebtInstrumentAxis=nav_TracFundingFacilityMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementBusinessSegmentsAxis=nav_FinancialServicesOperationsMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |