Note 3 - Securities - Amortized Cost and Fair Values of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Jun. 30, 2020
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	$ 4,525
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	4,602
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	13,129
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	13,596
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	17,662
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	18,060
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	44,817
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	46,880
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis	80,133
Available-for-sale Securities, Debt Maturities, Single Maturity Date	83,138
Available-for-sale securities, Amortized Cost Basis	165,601	$ 138,525
Total available-for-sale securities	169,059	143,918
Due after one year through five years, Net Carrying Amount	334
Due after one year through five years, Fair Value	350
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	5,367
Held-to-maturity Securities, Debt Maturities, Year Five Through Ten, Fair Value	5,686
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	2,335
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	2,447
Total held-to-maturity securities	8,036	3,541
Held-to-maturity Securities, Fair Value	8,483	$ 3,868
U.S. Government-sponsored Mortgage-backed and Related Securities [Member]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	85,468
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	$ 85,921