Contingent Liabilities, Commitments and Legal Matters (Detail) - USD ($) $ in Thousands	6 Months Ended
Jan. 31, 2020	Jul. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Standby repurchase obligations amount	$ 3,143,088	$ 2,961,019
Term of commitments	18 months
Repurchase and guarantee reserve balances	$ 9,466	$ 9,575

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