Income Taxes - Schedule of Deferred Income Taxes (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Depreciable assets	$ (2,257)	$ 1,618
Deferred revenue	80	96
Accruals and reserves	1,153	835
Stock-based compensation	3,113	4,194
Impaired strategic investments	2,701	4,186
Capital loss carryforward	63	1,456
NOL carryforward	3,324
Federal and state R&D credit	110
Other	587	586
Valuation allowance	(3,847)	(5,721)
Total deferred tax assets	5,027	7,250
Less current deferred tax assets		(546)
Noncurrent deferred tax assets	$ 5,027	$ 6,704