Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive (loss) income, Beginning Balance	$ (54,745)	$ (45,034)
Other comprehensive income before reclassification	10,250	(8,184)
Amounts reclassified from accumulated other comprehensive loss	187	1,527
Accumulated other comprehensive (loss) income, Ending Balance	(44,682)	(54,745)
Cash Flow Hedging [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive (loss) income, Beginning Balance	(857)	9
Other comprehensive income before reclassification	670	(986)
Amounts reclassified from accumulated other comprehensive loss	296	(120)
Accumulated other comprehensive (loss) income, Ending Balance	109	(857)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive (loss) income, Beginning Balance	(56,124)	(48,481)
Other comprehensive income before reclassification	8,713	(7,643)
Amounts reclassified from accumulated other comprehensive loss	0	0
Accumulated other comprehensive (loss) income, Ending Balance	(47,411)	(56,124)
Other Postretirement Benefit Plan, Defined Benefit [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive (loss) income, Beginning Balance	2,236	3,438
Other comprehensive income before reclassification	867	445
Amounts reclassified from accumulated other comprehensive loss	(483)	1,647
Accumulated other comprehensive (loss) income, Ending Balance	$ 2,620	$ 2,236