401(k) Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Defined Benefit Plan Disclosure [Line Items]
Annual base salary of employee		$ 8,000
Benefits charged to operating expenses	$ 382,000	180,000	$ 90,000
Scenario, Previously Reported [Member]
Defined Benefit Plan Disclosure [Line Items]
Annual base salary of employee		$ 4,000
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of annual contribution		3.00%
Maximum [Member] | Scenario, Previously Reported [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of annual contribution		2.00%