Schedule of Major Classifications of Inventories (Detail) - USD ($) $ in Thousands	Jan. 31, 2018	Jul. 31, 2017
Inventory [Line Items]
Work in process	$ 144,714	$ 117,319
Raw materials	257,765	214,518
Chassis	135,555	109,555
Subtotal	626,933	494,158
Excess of FIFO costs over LIFO costs	(36,570)	(33,670)
Total inventories, net	590,363	460,488
Recreational vehicles
Inventory [Line Items]
Finished goods	54,722	24,904
Other
Inventory [Line Items]
Finished goods	$ 34,177	$ 27,862