Inventories (Details) - USD ($)	Apr. 30, 2016	Jul. 31, 2015
Inventory Disclosure [Abstract]
Raw materials and components	$ 54,956,000	$ 51,272,000
Work-in-process and finished goods	36,514,000	27,700,000
Total inventories	91,470,000	78,972,000
Less reserve for excess and obsolete inventories	16,146,000	16,904,000
Inventories, net	75,324,000	62,068,000
Inventory directly related to long-term contracts	2,606,000	2,261,000
Inventory related to contracts from third party commercial customers who outsource their manufacturing to us	$ 1,234,000	$ 609,000