Schedule of Major Classifications of Inventories (Detail) - USD ($) $ in Thousands	Apr. 30, 2018	Jul. 31, 2017
Inventory [Line Items]
Work in process	$ 143,801	$ 117,319
Raw materials	263,613	214,518
Chassis	127,706	109,555
Subtotal	647,055	494,158
Excess of FIFO costs over LIFO costs	(39,870)	(33,670)
Total inventories, net	607,185	460,488
Recreational vehicles
Inventory [Line Items]
Finished goods	79,234	24,904
Other
Inventory [Line Items]
Finished goods	$ 32,701	$ 27,862