Components of Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jan. 31, 2019	Jul. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Cost	$ 569,727	$ 569,727
Accumulated Amortization	$ 206,496	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	$ 168,000	147,077
Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life	17 years
Cost	$ 146,117	146,117
Accumulated Amortization	$ 27,907	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	$ 10,161	9,555
Non-Compete Agreements
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life, Description	Less than 1
Cost	$ 450	450
Accumulated Amortization	$ 428	$ 383