Schedule of Deferred Income Taxes (Detail) - Noncurrent Deferred Income Tax Assets (Liabilities) - USD ($) $ in Thousands	Jul. 31, 2017	Jul. 31, 2016
Schedule of Deferred Income Tax Assets and Liabilities [Line Items]
Inventory basis	$ 1,460	$ 1,196
Employee benefits	6,471	4,587
Self-Insurance Reserves	9,940	10,504
Accrued product warranties	73,393	43,388
Accrued incentives	6,175	5,154
Sales returns and allowances	2,340	1,642
Accrued expenses	3,399	2,607
Property, plant and equipment	(8,151)	(4,164)
Deferred compensation	14,556	9,145
Intangibles	(17,184)	(22,308)
Unrecognized tax benefits	3,925	4,105
Other	(3,355)	(2,439)
Deferred income tax asset, net	$ 92,969	$ 53,417