Stockholders' Equity - Summary of Status of Company's Non-Vested Shares (Detail) - $ / shares	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Outstanding Beginning Balance (in shares)	2,029,741	1,805,443
Shares, Granted (in shares)	229,350	413,249
Options, Forfeited (in shares)	(604,662)	(174,619)
Options, Outstanding Ending Balance (in shares)	1,654,429	2,029,741
Weighted-Average Grant Date Fair Value, Granted (usd per share)	$ 0.28	$ 0.95
Non-Vested Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Outstanding Beginning Balance (in shares)	680,720	544,834
Shares, Granted (in shares)	229,350	413,249
Shares, Vested	(508,998)	(258,938)
Options, Forfeited (in shares)	(43,958)	(18,425)
Options, Outstanding Ending Balance (in shares)	357,114	680,720
Weighted-Average Grant Date Fair Value, Non-vested Beginning Balance	$ 1.46	$ 2.42
Weighted-Average Grant Date Fair Value, Granted (usd per share)	0.28	0.95
Weighted-Average Grant Date Fair Value, Vested	1.46	2.47
Weighted-Average Grant Date Fair Value, Forfeited	1.06	1.73
Weighted-Average Grant Date Fair Value, Non-vested Ending Balance	$ 0.77	$ 1.46