Income Taxes - Schedule of Deferred Income Taxes (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Depreciable assets	$ 1,618	$ 1,612
Deferred revenue	96	101
Accruals and reserves	145	324
Stock-based compensation	4,194	4,373
Impaired strategic investments	4,186	3,674
Unrealized gains on investments		(550)
Capital loss carryforward	1,456	1,650
Other	1,276	764
Valuation allowance	(5,721)	(4,836)
Total deferred tax assets	7,250	7,112
Less current deferred tax assets	(546)	(394)
Noncurrent deferred tax assets	$ 6,704	$ 6,718