Stock-Based Compensation - Summarize Information about Stock Options (Detail)	9 Months Ended
	Jun. 30, 2016 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options Outstanding, beginning balance | shares	5,435,640
Number of Options Outstanding, Granted | shares	1,387,000
Number of Options Outstanding, Cancelled | shares	(99,897)
Number of Options Outstanding, Exercised | shares	(4,687)
Number of Options Outstanding, ending balance | shares	6,718,056
Number of Options Outstanding, Exercisable | shares	3,563,564
Weighted Average Exercise Price Per Share, beginning balance | $ / shares	$ 6.71
Weighted Average Exercise Price Per Share, Granted | $ / shares	6.12
Weighted Average Exercise Price Per Share, Cancelled | $ / shares	9.86
Weighted Average Exercise Price Per Share, Exercised | $ / shares	5.45
Weighted Average Exercise Price Per Share, ending balance | $ / shares	6.54
Weighted Average Exercise Price Per Share, Exercisable | $ / shares	$ 6.16
Weighted Average Remaining Contractual Term	7 years 7 months 6 days
Weighted Average Remaining Contractual Term, Exercisable	6 years 7 months 6 days
Aggregate Intrinsic Value | $	$ 4,073,899
Aggregate Intrinsic Value, Exercisable | $	$ 3,304,194