Exercise price of the warrants.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column A

+ Details

Name:	invest_InvestmentWarrantsExercisePrice
Namespace Prefix:	invest_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument Convertible Conversion Ratio Basis

+ References

No definition available.

+ Details

Name:	nav_DebtInstrumentConvertibleConversionRatioBasis
Namespace Prefix:	nav_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Shares of Warrants Unwound

+ References

No definition available.

+ Details

Name:	nav_SharesofWarrantsUnwound
Namespace Prefix:	nav_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Shares related to convertible notes

+ References

No definition available.

+ Details

Name:	nav_SharesRelatedToConvertibleNotes
Namespace Prefix:	nav_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Shares related to warrants

+ References

No definition available.

+ Details

Name:	nav_SharesRelatedToWarrants
Namespace Prefix:	nav_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Antidilution

-URI http://asc.fasb.org/extlink&oid=6505113

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Diluted Earnings Per Share

-URI http://asc.fasb.org/extlink&oid=6510752

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Contingent Stock Agreement

-URI http://asc.fasb.org/extlink&oid=6508534

+ Details

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(i))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph i

-Article 4

+ Details

Name:	us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(5))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Conversion Rate

-URI http://asc.fasb.org/extlink&oid=6509012

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionRatio1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise or strike price stated in the contract for options indexed to the issuer's equity shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 480

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(1)

-URI http://asc.fasb.org/extlink&oid=6940734&loc=d3e22047-110879

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 40

-Section 50

-Paragraph 5

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6445032&loc=d3e90205-114008

+ Details

Name:	us-gaap_OptionIndexedToIssuersEquityStrikePrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=nav_FourPointFiveZeroSeniorSubordinatedConvertibleNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nav_FourPointSevenFiveSeniorSubordinatedConvertibleNotesMemberMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=nav_ThreePointZeroPercentSeniorSubordinatedConvertibleNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Loss Per Share Attributable to Navistar International Corporation - Narrative (Details) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended	12 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014	Oct. 31, 2009	Oct. 31, 2014	Jan. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares of Warrants Unwound	1,939,376nav_SharesofWarrantsUnwound	6,523,319nav_SharesofWarrantsUnwound
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	16,000,000	24,000,000	16,000,000	27,300,000
Shares related to warrants		4,800,000nav_SharesRelatedToWarrants		8,100,000nav_SharesRelatedToWarrants
Three Point Zero Percent Senior Subordinated Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares of Warrants Unwound	1,939,376	6,523,319
Class of Warrant or Right, Outstanding							2,900,000
Shares related to convertible notes		3,300,000		7,300,000
Three Point Zero Percent Senior Subordinated Convertible Notes [Member] \| Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt Instrument, Convertible, Conversion Ratio			19.891
Debt Instrument Convertible Conversion Ratio Basis			1,000
Option Indexed to Issuer's Equity, Strike Price					$ 50.27
Investment Warrants, Exercise Price			60.14
Four Point Five Zero Senior Subordinated Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares related to convertible notes	3,400,000	3,400,000	3,400,000	3,400,000
Four Point Five Zero Senior Subordinated Convertible Notes [Member] \| Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt Instrument, Convertible, Conversion Ratio			17.1233
Debt Instrument Convertible Conversion Ratio Basis			1,000
Debt Instrument, Convertible, Conversion Price							58.40
Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt Instrument, Convertible, Conversion Ratio			18.4946
Option Indexed to Issuer's Equity, Strike Price			54.07
Shares related to convertible notes	7,600,000		7,600,000	3,800,000		7,600,000
Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member] \| Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt Instrument Convertible Conversion Ratio Basis			1,000