Components of Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended
	Apr. 30, 2018	Jul. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Cost	$ 572,327	$ 572,327
Accumulated Amortization	$ 170,097	128,861
Dealer Network/Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	16 years
Cost	$ 404,960	404,960
Accumulated Amortization	$ 135,798	101,795
Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	18 years
Cost	$ 147,617	147,617
Accumulated Amortization	$ 23,649	17,570
Design Technology and Other Intangibles
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	7 years
Cost	$ 19,300	19,300
Accumulated Amortization	$ 10,290	9,203
Non-Compete Agreements
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	1 year
Cost	$ 450	450
Accumulated Amortization	$ 360	$ 293