Derivatives and Hedging Activities Notional Value of Derivatives Outstanding (Details) - USD ($) $ in Thousands |
9 Months Ended | |
|---|---|---|
Apr. 30, 2020 |
Jul. 31, 2019 |
|
| Derivative [Line Items] | ||
| Document Period End Date | Apr. 30, 2020 | |
| Derivative, Notional Amount | $ 24,240 | $ 29,389 |
| Designated as Hedging Instrument [Member] | ||
| Derivative [Line Items] | ||
| Derivative, Notional Amount | 21,533 | 26,013 |
| Not designated as hedging Instruments [Member] | ||
| Derivative [Line Items] | ||
| Derivative, Notional Amount | $ 2,707 | $ 3,376 |