Derivatives and Hedging Activities Notional Amount of Derivative Contracts (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Jul. 31, 2019
Derivative [Line Items]
Derivative, Notional Amount	$ 22,925	$ 29,389
Designated as hedging instruments [Member]
Derivative [Line Items]
Derivative, Notional Amount	19,540	26,013
Not designated as hedging Instruments [Member
Derivative [Line Items]
Derivative, Notional Amount	$ 3,385	$ 3,376