Basis of Presentation and Significant Accounting Policies - Summary of Status of Company's Non-Vested Shares (Detail)	9 Months Ended
	Jun. 30, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Outstanding Beginning Balance (in shares)	1,602,822
Shares, Granted (in shares)	315,020
Options, Forfeited (in shares)	(84,314)
Options, Outstanding Ending Balance (in shares)	1,833,528
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant Date Fair Value, Granted (in usd per share) | $ / shares	$ 1.83
Non-Vested Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Outstanding Beginning Balance (in shares)	539,985
Shares, Granted (in shares)	315,020
Shares, Vested (in shares)	(256,248)
Options, Forfeited (in shares)	(31,072)
Options, Outstanding Ending Balance (in shares)	567,685
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant Date Fair Value, Non-vested Beginning Balance (in usd per share) | $ / shares	$ 3.21
Weighted-Average Grant Date Fair Value, Granted (in usd per share) | $ / shares	1.83
Weighted-Average Grant Date Fair Value, Vested (in usd per share) | $ / shares	3.06
Weighted-Average Grant Date Fair Value, Forfeited (in usd per share) | $ / shares	2.58
Weighted-Average Grant Date Fair Value, Non-vested Ending Balance (in usd per share) | $ / shares	$ 2.50