Derivatives (Details) - Foreign currency forward contracts - Designated as hedging instrument - Fair value hedge instruments |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
|
Jan. 31, 2016
USD ($)
contract
|
Jan. 31, 2015
USD ($)
|
Jan. 31, 2016
USD ($)
contract
|
Jan. 31, 2015
USD ($)
|
|
| Derivatives | ||||
| Term of contracts | 1 month | |||
| Number of contracts | contract | 5 | 5 | ||
| Aggregate value of contracts | $ 12,783,000 | $ 12,783,000 | ||
| Term of renewed contracts | 1 month | |||
| Net currency conversion gains (losses), net of tax | $ (214,000) | $ 15,000 | $ (306,000) | $ (49,000) |