Long-Term Obligations - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Jul. 31, 2017	Jul. 31, 2016
Debt Instrument [Line Items]
Debt, long-term and short-term	$ 107,764	$ 216,910
Notes payable	(3,228)	(4,928)
Long-term debt	104,536	211,982
USD-denominated China line of credit [Member]
Debt Instrument [Line Items]
Notes payable	(34,336)	0
CNY-denominated China line of credit [Member]
Debt Instrument [Line Items]
Notes payable	(2,228)	(4,928)
USD-Denominated Borrowing Credit Revolver [Member]
Debt Instrument [Line Items]
Notes payable	(1,000)	0
Euro-denominated notes payable in 2017 at a fixed rate of 3.71% [Member]
Debt Instrument [Line Items]
Long-term debt	0	33,459
Euro-denominated notes payable in 2020 at a fixed rate of 4.24% [Member]
Debt Instrument [Line Items]
Long-term debt	53,202	50,188
USD-denominated notes payable through 2017 at a fixed rate of 5.33% [Member]
Debt Instrument [Line Items]
Long-term debt	0	16,335
USD-Denominated Borrowing Credit Revolver [Member]
Debt Instrument [Line Items]
Long-term debt	$ 16,998	$ 112,000