Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (71,254)	$ (56,401)
Other comprehensive (loss) income before reclassification	5,524	(13,498)
Amounts reclassified from accumulated other comprehensive loss	(747)	1,355
Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle	0	0	$ 1,869
Ending balance	(66,477)	(71,254)	(56,401)
Unrealized gain (loss) on cash flow hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	707	863
Other comprehensive (loss) income before reclassification	(447)	630
Amounts reclassified from accumulated other comprehensive loss	(460)	786
Ending balance	(200)	707	863
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(74,761)	(60,566)
Other comprehensive (loss) income before reclassification	6,303	(14,195)
Amounts reclassified from accumulated other comprehensive loss	0	0
Ending balance	(68,458)	(74,761)	(60,566)
Gain on post-retirement plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	2,800	3,302
Other comprehensive (loss) income before reclassification	(332)	67
Amounts reclassified from accumulated other comprehensive loss	(287)	569
Ending balance	$ 2,181	$ 2,800	$ 3,302