Basis of Presentation and Significant Accounting Policies - Summary of Option Activity (Detail) (USD $)	6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options, Outstanding Beginning Balance	1,240,941
Options, Granted	305,404
Options, Exercised	(6,867)
Options, Forfeited	(54,035)
Options, Outstanding Ending Balance	1,485,443
Options, Exercisable Ending Balance	880,746
Weighted Average Exercise Price, Outstanding Beginning Balance	$ 10.31
Weighted Average Exercise Price, Granted	$ 9.27
Weighted Average Exercise Price, Exercised	$ 6.98
Weighted Average Exercise Price, Forfeited	$ 12.34
Weighted Average Exercise Price, Outstanding Ending Balance	$ 10.04
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	7 years 9 months 18 days
Weighted Average Remaining Contractual Period in Years, Forfeited	3 years 2 months 12 days
Weighted Average Remaining Contractual Period in Years, Outstanding Ending Balance	7 years 1 month 6 days	6 years 10 months 24 days
Weighted Average Remaining Contractual Period in Years, Exercisable Ending Balance	5 years 9 months 18 days