Note 9 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2019
Income Tax Expense (Benefit), Total	$ 763,000	$ 454,000	$ 1,076,000	$ 849,000
Effective Income Tax Rate Reconciliation, Percent, Total	20.30%	25.90%	20.20%	24.10%
Unrecognized Tax Benefits, Ending Balance	$ 0		$ 0
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Valuation Allowance, Total	$ 47,000		$ 47,000		$ 47,000