Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Loss), Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (44,682)	$ (54,745)
Other comprehensive income (loss) before reclassification	(7,265)	(12,280)
Amounts reclassified from accumulated other comprehensive loss	115	(111)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax		0
Ending balance	(52,062)	(66,914)
Unrealized (loss) gain on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	109	(857)
Other comprehensive income (loss) before reclassification	(419)	328
Amounts reclassified from accumulated other comprehensive loss	(15)	(247)
Ending balance	(295)	(282)
Unamortized gain on post-retirement plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	2,620	2,236
Other comprehensive income (loss) before reclassification	0	0
Amounts reclassified from accumulated other comprehensive loss	130	136
Ending balance	2,490	2,100
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(47,411)	(56,124)
Other comprehensive income (loss) before reclassification	(6,846)	(12,608)
Amounts reclassified from accumulated other comprehensive loss	0
Ending balance	$ (54,257)	$ (68,732)