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Warrants and Derivative Liabilities - Additional Information (Detail) - USD ($)								1 Months Ended	3 Months Ended				6 Months Ended
	Apr. 29, 2015	Dec. 19, 2014	Nov. 13, 2014	Nov. 15, 2013	Oct. 09, 2013	Jun. 05, 2012	Apr. 04, 2012	Dec. 31, 2012	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014
Derivative [Line Items]
Exercise price	$ 9.41
Warrants to purchase one share of common stock			90.00%
Gain (loss) in change of fair value of derivative instruments and warrants									$ 701,000		$ 795,000		$ 1,501,000	$ 760,000
Warrants expiration date			Nov. 13, 2019	May 15, 2019		Dec. 05, 2017
Common stock units offered			909,090
Number of warrants issued to purchase common stock			818,181
Sale of stock, price per share			$ 11.00
Senior Secured Term Loan First Warrant
Derivative [Line Items]
Gain (loss) in change of fair value of derivative instruments and warrants											0			0
Senior Secured Term Loan New Warrant
Derivative [Line Items]
Gain (loss) in change of fair value of derivative instruments and warrants													100,000
Hudson Warrant
Derivative [Line Items]
Gain (loss) in change of fair value of derivative instruments and warrants									500,000				$ 1,200,000
Maximum | Senior Secured Term Loan New Warrant
Derivative [Line Items]
Gain (loss) in change of fair value of derivative instruments and warrants									100,000
Capital Ventures International
Derivative [Line Items]
Warrant exercise, waiting period													6 months
Warrant exercise period													5 years
Common stock, shares issued										909,090
Warrants to purchase one share of common stock										90.00%
Required notification period													61 days
Gain (loss) in change of fair value of derivative instruments and warrants									$ 100,000		800,000		$ 200,000	700,000
Senior Convertible Debt | Capital Ventures International
Derivative [Line Items]
Number of shares received from warrants received to purchase common stock							309,406
Exercise price	15.94				$ 26.10		$ 54.50			$ 22.10
New Unsecured Senior Convertible Note | Capital Ventures International | Minimum
Derivative [Line Items]
Beneficial ownership limitation percentage								4.99%
New Unsecured Senior Convertible Note | Capital Ventures International | Maximum
Derivative [Line Items]
Beneficial ownership limitation percentage								9.99%
Senior Secured Loan
Derivative [Line Items]
Number of shares received from warrants received to purchase common stock				25,641
Exercise price			$ 17.00	$ 19.50
Common stock, shares issued			909,090
Warrants to purchase one share of common stock			90.00%
Gain (loss) in change of fair value of derivative instruments and warrants											$ 100,000			$ 100,000
Senior Secured Loan | Hercules Technology Growth Capital
Derivative [Line Items]
Number of shares received from warrants received to purchase common stock		58,823
Exercise price	$ 9.41	$ 11.00	$ 17.00									$ 19.50
Common stock, shares issued			909,090
Warrants to purchase one share of common stock			90.00%
Warrants expiration date		Jun. 30, 2020
Senior Secured Loan | Term Loan | Hercules Technology Growth Capital
Derivative [Line Items]
Number of shares received from warrants received to purchase common stock						13,927
Exercise price						$ 35.90

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