Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017	Jan. 31, 2013	Dec. 31, 2012
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants outstanding	166,023
Contingent consideration obligations	$ 0		$ 0
2012 Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued to acquire Common Stock					912,543
Warrants cancelled upon expiration	143,811
2013 Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued to acquire Common Stock				833,530
Warrants outstanding	11,023
Warrant
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Non-cash gain (loss) from change in fair value of the derivative liability	$ 450,739	$ 1,454,831