Stockholders' Equity - Additional Information (Detail) - USD ($)			6 Months Ended
	Apr. 29, 2015	Nov. 13, 2014	Sep. 30, 2014	Sep. 30, 2015	Mar. 31, 2015	Nov. 15, 2013
Stockholders Equity [Line Items]
Common stock				$ 141,000	$ 96,000
Proceeds From Issuance Of Common Stock	$ 22,300,000	$ 9,100,000
Sale of stock, price per share		$ 11.00
Common stock units offered		909,090
Warrants to purchase one share of common stock		90.00%
Number of warrants issued to purchase common stock		818,181
MLV, & Co. LLC | At Market Sales Agreement
Stockholders Equity [Line Items]
Commission on sale of common stock under the ATM						3.00%
Proceeds From Issuance Of Common Stock			$ 4,900,000
Common stock, shares issued			290,741
Sale of stock, price per share			$ 17.16
Cowen and Company, LLC
Stockholders Equity [Line Items]
Proceeds From Issuance Of Common Stock	$ 22,300,000
Common stock, shares issued	4,000,000
Sale of stock, price per share	$ 6.00
Maximum | MLV, & Co. LLC | At Market Sales Agreement
Stockholders Equity [Line Items]
Common stock						$ 30,000,000