Property Plant and Equipment (Details) - USD ($)	12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 201,195,000	$ 186,326,000
Less accumulated depreciation and amortization	150,832,000	151,040,000
Property, plant and equipment, net	50,363,000	35,286,000
Depreciation and amortization	10,303,000	9,343,000	$ 10,386,000
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	186,935,000	170,600,000
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,260,000	$ 15,726,000