Derivative Notional Amounts (Details) - USD ($) $ in Thousands	Jul. 31, 2020	Jul. 31, 2019
Derivative [Line Items]
Derivative, Notional Amount	$ 27,707	$ 29,389
Designated as hedging instruments [Member]
Derivative [Line Items]
Derivative, Notional Amount	24,600	26,013
Not designated as hedging Instruments [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 3,107	$ 3,376