Employee Benefit Plans - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Effect of plan amendment on accumulated benefit obligation			$ 4,490
Curtailment gain	$ 0	$ 0	$ 4,296
Actuarial gain that will be amortized from AOCI into net periodic postretirement benefit cost over the next fiscal year	$ (520)
Weighted average discount rate used in determining accumulated postretirement benefit obligation	2.50%	2.50%	3.00%
Accumulated pension obligation	$ 3,390	$ 3,800	$ 4,135
Periodic postretirement benefit cost	(455)	(1,558)	(5,837)
Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated pension obligation	6,075	7,120
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax	641	1,161
Periodic postretirement benefit cost	665	795	724
Retirement and Profit Sharing Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accrued retirement and profit-sharing contributions	3,327	3,380
Pension and other postretirement benefit expense	13,750	10,407	$ 9,912
Deferred Compensation Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred compensation arrangement with individual, recorded liability	$ 14,121	$ 18,758