Defined Contributions and Other Post-Retirement Plans (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Employee 401(k) Plan (Textual) [Abstract]
Maximum Annual Contribution Per Employee, Percent	60.00%
Maximum Annual Contribution Per Employee, Amount	$ 5
Company's contributions	$ 10,700	$ 9,900	$ 8,700