|
Summary of Difference Between Tax Derived by Applying Federal Statutory Income Tax Rate (Detail) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Apr. 30, 2014
|
Jan. 31, 2014
|
Oct. 31, 2013
|
Jul. 31, 2013
|
Apr. 30, 2013
|
Jan. 31, 2013
|
Oct. 31, 2012
|
Jul. 31, 2012
|
Apr. 30, 2014
|
Apr. 30, 2013
|
Apr. 30, 2012
|
|
| Reconciliation of Statutory Federal Tax Rate [Line Items] | |||||||||||
| U.S. federal taxes at statutory rate | $ (18,138) | $ (16,550) | $ (7,996) | ||||||||
| State tax provision | (1,510) | 250 | 237 | ||||||||
| Foreign tax rate differentials | (123) | (185) | (110) | ||||||||
| Research and development credit | (1,201) | (1,198) | (613) | ||||||||
| Stock options | 1,608 | 3,752 | 1,448 | ||||||||
| Nondeductible legal expenses | 5,796 | 3,956 | |||||||||
| Permanent differences and other | (1,389) | 153 | 382 | ||||||||
| Change in valuation allowance | 14,457 | 8,650 | 7,463 | ||||||||
| Provision for (benefit from) income taxes | $ (418) | $ 179 | $ 130 | $ (391) | $ 583 | $ (2,295) | $ 271 | $ 269 | $ (500) | $ (1,172) | $ 811 |