Employee Benefit Plans - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Retirement and Profit Sharing Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and other postretirement benefit expense	$ 12,129	$ 14,158	$ 14,395
Accrued retirement and profit-sharing contributions	3,577	3,342
Deferred Compensation Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred compensation arrangement with individual, recorded liability	$ 18,606	$ 15,744