Note 4 - Loans - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021
Impaired Financing Receivable, Related Allowance	$ 3		$ 4
Impaired Financing Receivable, Unpaid Principal Balance	2,274		2,320
Impaired Financing Receivable, Recorded Investment	1,898		1,954
Impaired Financing Receivable, Average Recorded Investment	1,907	$ 1,971
Impaired Financing Receivable, Interest Income, Accrual Method	7	12
Impaired Financing Receivable, Interest Income, Cash Basis Method	7	12
Commercial Portfolio Segment [Member]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	421		421
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	298		303
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	299	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	130		133
Impaired Financing Receivable, with Related Allowance, Recorded Investment	131		134
Impaired Financing Receivable, Related Allowance	3		1
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	131	171
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	2	2
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	2	2
Commercial Real Estate Portfolio Segment [Member] | Other Commercial Real Estate Loans [Member]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,053		1,062
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	911		921
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	914	826
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	3	1
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	3	1
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance			0
Impaired Financing Receivable, with Related Allowance, Recorded Investment			0
Impaired Financing Receivable, Related Allowance			0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment		206
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method		3
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method		3
Residential Portfolio Segment [Member] | Residential Real Estate Owner Occupied Loans [Member]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	403		409
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	359		367
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	363	539
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	2	6
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	2	6
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance			28
Impaired Financing Receivable, with Related Allowance, Recorded Investment			27
Impaired Financing Receivable, Related Allowance			3
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment		0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method		0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method		0
Residential Portfolio Segment [Member] | Residential Real Estate Non-owner Occupied Loans [Member]
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	267		267
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	199		$ 202
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	200	229
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	$ 0	$ 0