Long-Term Obligations - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Jul. 31, 2018	Jul. 31, 2017
Debt Instrument [Line Items]
Debt, long-term and short-term	$ 52,618	$ 107,764
Notes payable	0	(3,228)
Long-term debt	52,618	104,536
USD-denominated China line of credit [Member]
Debt Instrument [Line Items]
Notes payable	0	(34,336)
CNY-denominated China line of credit [Member]
Debt Instrument [Line Items]
Notes payable	0	(2,228)
USD-Denominated Borrowing Credit Revolver [Member]
Debt Instrument [Line Items]
Notes payable	0
Euro-denominated notes payable in 2020 at a fixed rate of 4.24% [Member]
Debt Instrument [Line Items]
Long-term debt	52,618	53,202
USD-Denominated Borrowing Credit Revolver [Member]
Debt Instrument [Line Items]
Long-term debt	$ 0	$ 16,998