Schedule of Major Classifications of Inventories (Detail) - USD ($) $ in Thousands	Apr. 30, 2017	Jul. 31, 2016
Inventory [Line Items]
Work in process	$ 128,493	$ 97,872
Raw materials	209,501	173,362
Chassis	101,389	102,686
Total	491,678	434,004
Excess of FIFO costs over LIFO costs	(32,010)	(30,135)
Total inventories, net	459,668	403,869
Recreational vehicles
Inventory [Line Items]
Finished goods	27,394	39,943
Other
Inventory [Line Items]
Finished goods	$ 24,901	$ 20,141