Accrued Expenses and Other Current Liabilities (Components) (Details) - USD ($)	Oct. 31, 2020	Jul. 31, 2020	Oct. 31, 2019	Jul. 31, 2019
Payables and Accruals [Abstract]
Accrued wages and benefits	$ 19,613,000	$ 20,857,000
Accrued contract costs	12,707,000	15,306,000
Accrued warranty obligations	16,196,000	15,200,000	$ 16,068,000	$ 15,968,000
Accrued legal costs	2,593,000	2,539,000
Accrued commissions and royalties	4,576,000	4,621,000
Accrued acquisition plan expenses	22,794,000	7,014,000
Other	11,432,000	19,624,000
Accrued expenses and other current liabilities	$ 89,911,000	$ 85,161,000