Employee Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Employee benefits costs	$ 863,080	$ 545,698	$ 451,623
Employee Contributions up to 3%
Defined Benefit Plan Disclosure [Line Items]
Discretionary match percentage	100.00%
Percentage of compensation	3.00%
Employee Contributions Next 2%
Defined Benefit Plan Disclosure [Line Items]
Discretionary match percentage	50.00%
Percentage of compensation	2.00%