Accrued Expenses and Other Current Liabilities (Components) (Details) - USD ($)	Jan. 31, 2021	Jul. 31, 2020	Jan. 31, 2020	Jul. 31, 2019
Payables and Accruals [Abstract]
Accrued wages and benefits	$ 26,623,000	$ 20,857,000
Accrued contract costs	13,240,000	15,306,000
Accrued warranty obligations	16,674,000	15,200,000	$ 16,728,000	$ 15,968,000
Accrued legal costs	2,986,000	2,539,000
Accrued commissions and royalties	5,225,000	4,621,000
Accrued acquisition plan expenses	3,376,000	7,014,000
Other	11,061,000	19,624,000
Accrued expenses and other current liabilities	$ 79,185,000	$ 85,161,000