Income Taxes - Summary of Difference Between Tax Derived by Applying Federal Statutory Income Tax Rate (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
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Apr. 30, 2016 |
Jan. 31, 2016 |
Oct. 31, 2015 |
Jul. 31, 2015 |
Apr. 30, 2015 |
Jan. 31, 2015 |
Oct. 31, 2014 |
Jul. 31, 2014 |
Apr. 30, 2016 |
Apr. 30, 2015 |
Apr. 30, 2014 |
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| Income Tax Disclosure [Abstract] | |||||||||||
| U.S. federal taxes at statutory rate | $ (8,603) | $ (11,257) | $ (18,138) | ||||||||
| State tax provision | (625) | (923) | (1,510) | ||||||||
| Foreign tax rate differentials | (108) | (206) | (123) | ||||||||
| Research and development credit | (1,473) | (1,972) | (1,201) | ||||||||
| Stock options | 3,480 | 506 | 1,608 | ||||||||
| Nondeductible legal expenses | 0 | 200 | 5,796 | ||||||||
| Permanent differences and other | 0 | (8) | (1,389) | ||||||||
| Return to provision adjustments | 9 | 0 | 0 | ||||||||
| Change in valuation allowance | 7,358 | 13,714 | 14,457 | ||||||||
| Provision for (benefit from) income taxes | $ 165 | $ (163) | $ 124 | $ (88) | $ (540) | $ 324 | $ 258 | $ 12 | $ 38 | $ 54 | $ (500) |
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- Definition Effective Income Tax Rate Reconciliation, Return to Provision Adjustments, Amount No definition available.
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- References No definition available.
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to foreign income tax expense (benefit). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other nondeductible expenses. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible equity-based compensation costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to state and local income tax expense (benefit). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to research tax credit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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