Provision For Income Taxes - Additional information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Oct. 31, 2012	Oct. 31, 2011
Income Taxes [Line Items]
Maximum percentage of tax benefits realized upon ultimate settlement	50.00%
Decreases in unrecognized tax benefits resulting from lapses of the applicable statutes of limitations	$ 247
Gross uncertain tax benefit reserve and related interest and penalties	362
Effective income tax rate	34.90%	35.50%
Anticipated decrease in unrecognized tax benefits	3,641
Accrued interest and penalties related to unrecognized tax benefits	901
Minimum
Income Taxes [Line Items]
Anticipated decrease in unrecognized tax benefits possible range	3,200
Accrued interest and penalties related to unrecognized tax benefits possible range	1,800
Maximum
Income Taxes [Line Items]
Anticipated decrease in unrecognized tax benefits possible range	12,900
Accrued interest and penalties related to unrecognized tax benefits possible range	$ 5,800

Name:	tho_IncomeTaxesLineItems
Namespace Prefix:	tho_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Maximum percentage of tax benefits realized upon ultimate settlement.

+ References

No definition available.

+ Details

Name:	tho_MaximumPercentageOfTaxBenefitsRealizedUponUltimateSettlement
Namespace Prefix:	tho_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This is the reasonable possible range of decreases in the next 12 months.

+ References

No definition available.

+ Details

Name:	tho_UnrecognizedTaxBenefitsExpectedToBeRecognizedIncreaseDecrease
Namespace Prefix:	tho_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Unrecognized Tax Benefits Expected to be Recognized in Next Fiscal Year Increase (Decrease)

+ References

No definition available.

+ Details

Name:	tho_UnrecognizedTaxBenefitsExpectedToBeRecognizedInNextFiscalYearIncreaseDecrease
Namespace Prefix:	tho_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

This is the reasonable possible range of decreases for the next 12 months on unrecognized tax benefits.

+ References

No definition available.

+ Details

Name:	tho_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccruedExpectedToBeRecognized
Namespace Prefix:	tho_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued Expected To Be Recognized In Next Fiscal Year

+ References

No definition available.

+ Details

Name:	tho_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccruedExpectedToBeRecognizedInNextFiscalYear
Namespace Prefix:	tho_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Subparagraph 2

-Article 4

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 47

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 13

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319

Reference 5: 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.(h)(2))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

+ Details

Name:	us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the total of interest expense recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity and the amount of statutory penalties in the period in which the entity claims or expects to claim a tax position, in its tax return, that does not meet the minimum statutory threshold to avoid payment of penalties.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 48

-Paragraph 21

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 48

-Paragraph 15, 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The gross amount of decreases in unrecognized tax benefits resulting from lapses of the applicable statutes of limitations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15A

-Subparagraph (a)(4)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 48

-Paragraph 21

-Subparagraph a(4)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration