Components of Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2018	Jul. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Cost	$ 569,727	$ 569,727
Accumulated Amortization	$ 193,970	181,379
Dealer Network/Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	15 years
Cost	$ 404,960	404,960
Accumulated Amortization	$ 157,571	147,077
Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	17 years
Cost	$ 146,117	146,117
Accumulated Amortization	$ 26,136	24,364
Design Technology and Other Intangibles
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	7 years
Cost	$ 18,200	18,200
Accumulated Amortization	$ 9,858	9,555
Non-Compete Agreements
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	1 year
Cost	$ 450	450
Accumulated Amortization	$ 405	$ 383