v3.8.0.1

Income Taxes - Schedule of Deferred Income Taxes (Detail) - USD ($) $ in Thousands | Sep. 30, 2017 | Sep. 30, 2016
--- | --- | ---
Income Tax Disclosure [Abstract] |  |
Depreciable assets | $ (3,335) | $ (2,257)
Accruals and reserves | 1,123 | 1,153
Stock-based compensation | 3,370 | 3,113
Impaired strategic investments | 2,701 | 2,701
NOL carryforwards | 3,627 | 3,324
U.S. Federal and state R&D credits | 242 | 110
Other | 810 | 730
Valuation allowance | (4,511) | (3,847)
Total deferred tax assets | $ 4,027 | $ 5,027

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