Note 3 - Securities - Amortized Cost and Fair Values of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	$ 6,532
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	6,558
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	17,026
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	17,611
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	15,159
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	15,865
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	32,707
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	34,992
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis	71,424
Available-for-sale Securities, Debt Maturities, Single Maturity Date	75,026
Available-for-sale securities, Amortized Cost Basis	131,440	$ 138,525
Total available-for-sale securities	136,903	143,918
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	373
Held-to-maturity Securities, Debt Maturities, Year Five Through Ten, Fair Value	397
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	3,068
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	3,337
Total held-to-maturity securities	3,441	3,541
Held-to-maturity Securities, Fair Value	3,734	$ 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	60,016
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	$ 61,877