Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
IncomeTaxes [Line Items]
Total incomes taxes paid	$ 1,963,000	$ 3,850,000
Unrecognized tax benefits	150,000	150,000
Additional accruals of UTB's	0	0
Additional accruals of interest expense nor penalties	$ 0	$ 0
Effective income tax rate	12.50%	17.20%
Income Taxes Paid	$ 1,963,000	$ 3,850,000
Federal [Member]
IncomeTaxes [Line Items]
R&D tax credits carryforwards	0	0
R&D Credits	$ 335,000	421,000
Internal Revenue Service (IRS) [Member]
IncomeTaxes [Line Items]
Total incomes taxes paid		2,050,000
Income Taxes Paid		$ 2,050,000