Note 5 - Investment Securities (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Marketable Securities, Realized Gain (Loss), Excluding Other than Temporary Impairments, Total	$ 39,500	$ 10,900	$ 74,300	$ 36,200
Proceeds from Sale of Other Investments	3,000,000.0	$ 2,000,000.0	9,100,000	$ 3,000,000.0
Federal Home Loan Bank Borrowings [Member]
Pledged Assets Separately Reported, Securities Pledged for Federal Home Loan Bank, at Fair Value	13,200,000		13,200,000
Federal Home Loan Bank Borrowings [Member] | Asset Pledged as Collateral [Member]
Marketable Securities, Total	13,200,000		13,200,000
Federal Reserve Bank of Cleveland Borrowings [Member]
Pledged Assets Separately Reported, Securities Pledged for Federal Home Loan Bank, at Fair Value	33,700,000		33,700,000
Investment Securities Pledged as Collateral, Excess Collateral	33,600,000		33,600,000
Investment Securities Pledged as Collateral, Excess Collateral, Fair Value	33,700,000		33,700,000
Federal Reserve Bank of Cleveland Borrowings [Member] | Asset Pledged as Collateral [Member]
Marketable Securities, Total	$ 33,600,000		$ 33,600,000