Note 3 - Securities - Amortized Cost and Fair Values of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	$ 5,861
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	5,905
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	17,042
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	17,661
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	16,057
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	16,748
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	32,764
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	34,966
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis	71,724
Available-for-sale Securities, Debt Maturities, Single Maturity Date	75,280
Total available-for-sale securities, Amortized Cost Basis	138,525	$ 142,028
Total available-for-sale securities	143,918	144,010
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	373
Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value	398
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	3,168
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	3,470
Held-to-maturity Securities	3,541	3,786
Held-to-maturity Securities, Fair Value	3,868	$ 3,821
U.S. Government-sponsored Mortgage-backed and Related Securities [Member]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	66,801
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	$ 68,638