Inventories (Details) - USD ($)	Jan. 31, 2022	Jul. 31, 2021
Inventory Disclosure [Abstract]
Raw materials and components	$ 66,162,000	$ 62,249,000
Work-in-process and finished goods	46,073,000	38,338,000
Total inventories	112,235,000	100,587,000
Less reserve for excess and obsolete inventories	21,961,000	20,229,000
Inventories, net	90,274,000	80,358,000
Inventory directly related to long-term contracts	8,567,000	7,028,000
Inventory related to contracts from third party commercial customers who outsource their manufacturing to us	$ 1,700,000	$ 1,509,000