Cost Reduction Actions (Details) - USD ($)	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Restructuring Cost and Reserve [Line Items]
Facility exit costs	$ 1,373,000
Cash payments	805,000
Estimated contract settlement costs	6,351,000	$ 0	$ 0
Other Current Liabilities
Restructuring Cost and Reserve [Line Items]
Remaining estimated facility exit costs	$ 568,000