Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (56,401)	$ (44,682)
Other comprehensive income (loss) before reclassification	(13,498)	(13,395)
Amounts reclassified from accumulated other comprehensive loss	(1,355)	193
Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle	0	1,869	$ 0
Ending balance	(71,254)	(56,401)	(44,682)
Unrealized gain (loss) on cash flow hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	863	109
Other comprehensive income (loss) before reclassification	630	465
Amounts reclassified from accumulated other comprehensive loss	(786)	(383)
Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle		(94)
Ending balance	707	863	109
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(60,566)	(47,411)
Other comprehensive income (loss) before reclassification	(14,195)	(14,242)
Amounts reclassified from accumulated other comprehensive loss	0	0
Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle		1,087
Ending balance	(74,761)	(60,566)	(47,411)
Gain on post-retirement plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	3,302	2,620
Other comprehensive income (loss) before reclassification	67	382
Amounts reclassified from accumulated other comprehensive loss	(569)	576
Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle		876
Ending balance	$ 2,800	$ 3,302	$ 2,620