Nature of Operations and Summary of Significant Accounting Policies - Components of Comprehensive Loss (Detail) - USD ($)	3 Months Ended												12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Comprehensive Income Net Of Tax [Abstract]
Net income (loss)	$ 955,348	$ 916,961	$ 507,650	$ 146,180	$ 2,049	$ (1,632,601)	$ (2,193,017)	$ (1,468,300)	$ (1,470,730)	$ (2,052,059)	$ (2,393,275)	$ (1,359,642)	$ 2,526,139	$ (5,291,869)	$ (7,275,706)
Other comprehensive loss:
Foreign currency translation adjustment													(318)	0
Change in unrealized gain (loss) on investments													4,887	(9,648)	2,454
Total comprehensive loss													$ 2,530,708	$ (5,301,517)	$ (7,273,252)