Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Loss), Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2018	Oct. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (56,401)	$ (44,682)
Other comprehensive loss before reclassification	(9,640)	(7,265)
Amounts reclassified from accumulated other comprehensive loss	190	115
Ending balance	(66,231)	(52,062)
Unrealized gain on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	863	109
Other comprehensive loss before reclassification	(491)	(419)
Amounts reclassified from accumulated other comprehensive loss	35	(15)
Ending balance	337	(295)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(60,566)	(47,411)
Other comprehensive loss before reclassification	(9,149)	(6,846)
Ending balance	(69,715)	(54,257)
Unamortized gain on post-retirement plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	3,302	2,620
Amounts reclassified from accumulated other comprehensive loss	155	130
Ending balance	$ 3,147	$ 2,490