Inventories, Net (Details) - USD ($)	Apr. 30, 2017	Jul. 31, 2016
Inventories, Net
Raw materials and parts	$ 46,038,000	$ 45,867,000
Work-in-process	13,613,000	13,178,000
Finished goods	51,011,000	37,831,000
Reserve for excess and obsolete inventory	(7,857,000)	(5,390,000)
Total inventories	$ 102,805,000	$ 91,486,000