Contingent Liabilities, Commitments and Legal Matters (Detail) - USD ($) $ in Thousands	9 Months Ended
Apr. 30, 2021	Jul. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Standby repurchase obligations amount	$ 2,149,930	$ 1,876,922
Term of commitments	18 months
Repurchase and guarantee reserve balances	$ 7,302	$ 7,747

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:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration