Income Taxes - Schedule of Deferred Income Taxes (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Depreciable assets	$ (1,964)	$ (905)
Deferred revenue	2,029	1,554
Accruals and reserves	1,858	585
Stock-based compensation	2,232	2,213
Impaired strategic investments	1,767	1,666
NOL carryforwards	3,526	3,308
U.S. Federal and State R&D credits	3,216	2,394
Other	897	689
Valuation allowance	(6,246)	(5,328)
Total deferred tax assets	$ 7,315	$ 6,176	$ 6,304

Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, with jurisdictional netting.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from in-process research and development costs expensed in connection with a business combination.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from property, plant, and equipment.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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