Stockholders' Equity - Summary of Warrant Activity (Detail) (USD $)	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Class of Warrant or Right [Line Items]
Shares of Common Stock Purchasable Upon Exercise of Warrants, Beginning Balance	1,201,116	6,155,170
Shares of Common Stock Purchasable Upon Exercise of Warrants, Issued		491,007
Shares of Common Stock Purchasable Upon Exercise of Warrants, Exercised	(1,147,159)	(5,445,061)
Shares of Common Stock Purchasable Upon Exercise of Warrants, Ending Balance	53,957	1,201,116
Weighted Average Exercise Price per Share, Beginning Balance	$ 1.98	$ 1.43
Weighted Average Exercise Price per Share, Issued		$ 2.78
Weighted Average Exercise Price per Share, Exercised	$ 1.94	$ 1.43
Weighted Average Exercise Price per Share, Ending Balance	$ 2.78	$ 1.98
Range of Exercise Prices, Beginning Balance		$ 1.43
Range of Exercise Prices, Issued		$ 2.78
Range of Exercise Prices, Exercised		$ 1.43
Range of Exercise Prices, Ending Balance	$ 2.78
Minimum [Member]
Class of Warrant or Right [Line Items]
Range of Exercise Prices, Exercised	$ 1.43
Range of Exercise Prices, Ending Balance		$ 1.43
Maximum [Member]
Class of Warrant or Right [Line Items]
Range of Exercise Prices, Exercised	$ 2.78
Range of Exercise Prices, Ending Balance		$ 2.78