Contingent Liabilities, Commitments and Legal Matters (Detail) - USD ($) $ in Thousands	3 Months Ended
Oct. 31, 2020	Jul. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Standby repurchase obligations amount	$ 1,614,954	$ 1,876,922
Term of commitments	18 months
Repurchase and guarantee reserve balances	$ 6,308	$ 7,747

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

No definition available.

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Namespace Prefix:	tho_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration