Income Taxes - Additional Information (Detail) - USD ($) |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Apr. 30, 2017 |
Apr. 30, 2016 |
Apr. 30, 2017 |
Apr. 30, 2016 |
Jul. 31, 2016 |
|
| Income Taxes [Line Items] | |||||
| U.S. Federal statutory tax rate | 35.00% | 35.00% | 35.00% | 35.00% | |
| Discrete tax benefit | $ (200,000) | $ 1,100,000 | |||
| Unrecognized tax benefits, accrued interest and penalties | $ 300,000 | $ 300,000 | $ 400,000 | ||
| Unrecognized tax benefits, for uncertain tax positions | 6,900,000 | 6,900,000 | |||
| Maximum | |||||
| Income Taxes [Line Items] | |||||
| Discrete tax benefit | $ 500,000 | $ 900,000 | |||