Summary of Inventories, Net (Detail) - USD ($) $ in Thousands	Jan. 31, 2017	Jul. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 7,053	$ 7,429
Work in process	1,215	1,195
Supplies	970	968
Finished products	27,310	28,463
Less: reserve for inventory obsolescence	(678)	(654)
Inventories, net	$ 35,870	$ 37,401