| **Allowance for doubtful accounts**            | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Allowance for Doubtful Accounts [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Allowance for doubtful accounts                | Allowance for Doubtful AccountsWe have two portfolio segments of finance receivables based on the type of financing inherent to each portfolio. The retail portfolio segment represents loans or leases to end-users for the purchase or lease of vehicles. The wholesale portfolio segment represents loans to dealers to finance their inventory. Each portfolio consists of one class of receivable based on: (i) initial measurement attributes of the receivables, and (ii) the assessment and monitoring of risk and performance of the receivables.The activity related to our allowance for doubtful accounts for our retail portfolio, wholesale portfolio, and trade and other receivables is summarized as follows: Three Months Ended April 30, 2012 Three Months Ended April 30, 2011 RetailPortfolio WholesalePortfolio Trade andOtherReceivables Total RetailPortfolio WholesalePortfolio Trade andOtherReceivables Total(in millions)               Allowance for doubtful accounts, at beginning of period$28 $3 $16 $47 $54 $2 $38 $94Provision for doubtful accounts, net of recoveries— (1) 1 — 1 — (3) (2)Charge-off of accounts(A)(2) — — (2) (15) — (1) (16)Allowance for doubtful accounts, at end of period$26 $2 $17 $45 $40 $2 $34 $76 Six Months Ended April 30, 2012 Six Months Ended April 30, 2011 RetailPortfolio WholesalePortfolio Trade andOtherReceivables Total RetailPortfolio WholesalePortfolio Trade andOtherReceivables Total(in millions)               Allowance for doubtful accounts, at beginning of period$31 $3 $16 $50 $58 $2 $36 $96Provision for doubtful accounts, net of recoveries(2) (1) 3 — (1) — (1) (2)Charge-off of accounts(A)(3) — (2) (5) (17) — (1) (18)Allowance for doubtful accounts, at end of period$26 $2 $17 $45 $40 $2 $34 $76_________________________(A)We repossess sold and leased vehicles on defaulted finance receivables and leases, and place them into Inventories. Losses recognized at the time of repossession and charged against the allowance for doubtful accounts were $2 million and $3 million for the three and six months ended April 30, 2012, respectively, and $12 million and $15 million for the three and six months ended April 30, 2011, respectively.The accrual of interest income is discontinued on certain impaired finance receivables. Impaired finance receivables include accounts with specific loss reserves and certain accounts that are on non-accrual status. In certain cases, we continue to collect payments on our impaired finance receivables.Information regarding impaired finance receivables is as follows: As of  April 30, 2012 October 31, 2011 RetailPortfolio WholesalePortfolio Total RetailPortfolio WholesalePortfolio Total(in millions)           Impaired finance receivables with specific loss reserves$16 $— $16 $15 $— $15Impaired finance receivables without specific loss reserves1 — 1 2 — 2Specific loss reserves on impaired finance receivables10 — 10 10 — 10Finance receivables on non-accrual status12 — 12 14 — 14For the impaired finance receivables in the retail portfolio as of April 30, 2012 and 2011, the average balances of those receivables were $17 million and $39 million during the six months ended April 30, 2012 and 2011, respectively.The Company uses the aging of our receivables as well as other inputs when assessing credit quality. The aging analysis for finance receivables is summarized as follows: As of April 30, 2012 October 31, 2011 RetailPortfolio WholesalePortfolio Total RetailPortfolio WholesalePortfolio Total(in millions)           Current$1,307 $1,281 $2,588 $1,515 $1,328 $2,84330-90 days past due65 2 67 85 5 90Over 90 days past due12 1 13 13 1 14Total finance receivables$1,384 $1,284 $2,668 $1,613 $1,334 $2,947 |

| X                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**nav_AllowanceForDoubtfulAccountsAbstract**Namespace Prefix:**nav_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tabular disclosure of financing receivables (examples of financing receivables include loans, trade accounts receivable and notes receivable) and activity in the allowance for credit losses account.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -URI http://asc.fasb.org/extlink&oid=6965416&loc=SL6953423-111524
+ Details**Name:**us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock**Namespace Prefix:**us-gaap_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |