Contingent Liabilities and Commitments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jan. 31, 2015	Jul. 31, 2014
Loss Contingencies [Line Items]
Standby Repurchase Obligations Amount	$ 1,496,008	$ 1,226,650
Term of Commitments	Up to eighteen months
Repurchase and guarantee reserve balances	$ 4,690	$ 3,948

Terms of commitments under repurchase agreements for the repurchase of products sold to dealers.

No definition available.

Name:	tho_TermsOfCommitmentsUnderRepurchaseAgreementsForRepurchaseOfProductsSoldToDealers
Namespace Prefix:	tho_
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration