Severance and Other Restructuring Costs - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | 9 Months Ended | |
|---|---|---|---|---|
Apr. 30, 2017 |
Apr. 30, 2016 |
Apr. 30, 2017 |
Apr. 30, 2017 |
|
| Restructuring Cost and Reserve [Line Items] | ||||
| Restructuring charges | $ 2,147 | $ 1,775 | ||
| Restructuring Plan [Member] | ||||
| Restructuring Cost and Reserve [Line Items] | ||||
| Restructuring charges | $ 5,200 | |||
| Estimated restructuring costs | 5,300 | $ 5,300 | $ 5,300 | |
| Severance costs | $ 2,100 | |||
| DCC Labs [Member] | ||||
| Restructuring Cost and Reserve [Line Items] | ||||
| Restructuring charges | $ 1,900 | |||