Stock-Based Compensation - Summarize Information about Stock Options (Detail) (USD $)	9 Months Ended	12 Months Ended
	Jun. 30, 2014	Sep. 30, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options Outstanding, beginning balance	3,419,285	1,910,794
Number of Options Outstanding, Granted	930,000	1,509,166
Number of Options Outstanding, Cancelled	(148,561)
Number of Options Outstanding, Exercised	(377,112)	(675)
Number of Options Outstanding, ending balance	3,823,612	3,419,285
Number of Options Outstanding, Exercisable	1,532,180
Weighted Average Exercise Price Per Share, beginning balance	$ 4.68	$ 6.10
Weighted Average Exercise Price Per Share, Granted	$ 14.05	$ 2.03
Weighted Average Exercise Price Per Share, Cancelled	$ 5.88
Weighted Average Exercise Price Per Share, Exercised	$ 6.28	$ 3.93
Weighted Average Exercise Price Per Share, ending balance	$ 6.75	$ 4.68
Weighted Average Exercise Price Per Share, Exercisable	$ 5.80
Weighted Average Remaining Contractual Term	8 years 3 months 18 days
Weighted Average Remaining Contractual Term, Exercisable	7 years 3 months 18 days
Aggregate Intrinsic Value	$ 30,271,011
Aggregate Intrinsic Value, Exercisable	$ 13,666,712