Note 3 - Securities - Amortized Cost and Fair Values of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jun. 30, 2019
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	$ 8,341
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	8,401
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	15,554
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	15,963
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	13,703
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	14,023
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	31,692
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	33,171
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis	69,290
Available-for-sale Securities, Debt Maturities, Single Maturity Date	71,558
Total available-for-sale securities, Amortized Cost Basis	134,942	$ 142,028
Total available-for-sale securities	139,383	144,010
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	412
Held-to-maturity Securities, Debt Maturities, Year Five Through Ten Years, Fair Value	430
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	3,362
Held-to-maturity Securities	3,580	3,786
Total held-to-maturity securities, Fair Value	3,792	$ 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	65,652
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	$ 67,825