Stockholders' Equity - Stock-Based Compensation Expense Related to Stock Options and RSUs (Detail) - USD ($)	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense included in operating expenses	$ 988,857	$ 814,060
Sales and Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense included in operating expenses	243,027	175,118
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense included in operating expenses	180,642	137,406
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense included in operating expenses	$ 565,188	$ 501,536