Basis of Presentation and Significant Accounting Policies - Summary of Option Activity (Detail) - $ / shares	9 Months Ended	12 Months Ended
	Jun. 30, 2015	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options, Outstanding Beginning Balance	1,240,941
Options, Granted	313,954
Options, Exercised	(11,117)
Options, Forfeited	(74,051)
Options, Outstanding Ending Balance	1,469,727	1,240,941
Options, Exercisable Ending Balance	865,629
Weighted Average Exercise Price, Outstanding Beginning Balance	$ 10.31
Weighted Average Exercise Price, Granted	9.26
Weighted Average Exercise Price, Exercised	7.28
Weighted Average Exercise Price, Forfeited	11.90
Weighted Average Exercise Price, Outstanding Ending Balance	10.03	$ 10.31
Weighted Average Exercise Price, Exercisable Ending Balance	$ 10.52
Weighted Average Remaining Contractual Period in Years, Granted	9 years 9 months 18 days
Weighted Average Remaining Contractual Period in Years, Exercised	6 years 10 months 24 days
Weighted Average Remaining Contractual Period in Years, Forfeited	4 years 2 months 12 days
Weighted Average Remaining Contractual Period in Years, Outstanding Ending Balance	6 years 9 months 18 days	6 years 10 months 24 days
Weighted Average Remaining Contractual Period in Years, Exercisable Ending Balance	5 years 7 months 6 days