Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

INTANGIBLE ASSETS, GOODWILL AND LONG-LIVED ASSETS - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jan. 31, 2020	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Intangible Assets And Goodwill [Line Items]
Impairment charges		$ 10,057	$ 0	$ 0
Pre-tax, non-cash goodwill impairment charge		$ 1,036
Towables
Intangible Assets And Goodwill [Line Items]
Impairment charges	$ 10,057
Pre-tax, non-cash goodwill impairment charge	$ 1,036