Employee Benefit Plans - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	$ 4,984	$ 5,504
Actuarial gain that will be amortized from AOCI into net periodic postretirement benefit cost over the next fiscal year	$ (497)
Weighted average discount rate used in determining accumulated postretirement benefit obligation	2.50%	2.50%	2.50%
Accumulated pension obligation	$ 3,020	$ 3,390	$ 3,800
Periodic postretirement benefit cost	(441)	(455)	(1,558)
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	14,395	13,750	10,407
Accrued retirement and profit-sharing contributions	3,844	3,327
Deferred Compensation Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred compensation arrangement with individual, recorded liability	14,383	14,121
Foreign Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated pension obligation	5,383	6,075
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax	194	641
Periodic postretirement benefit cost	$ 341	$ 665	$ 795