Income Taxes - Schedule of Deferred Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Depreciable assets	$ 1,612	$ 1,271
Deferred revenue	101	74
Accruals and reserves	324	353
Stock-based compensation	4,373	4,220
Impaired strategic investments	3,674	3,253
Unrealized gains on investments	(550)	(29)
Capital loss carryforward	1,650	1,962
Other	764	733
Valuation allowance	(4,836)	(5,293)
Total deferred tax assets	7,112	6,544
Less current deferred tax assets	(394)	(506)
Noncurrent deferred tax assets	6,718	6,038
Total deferred tax assets	$ 7,112	$ 6,544