Note 5 - Fair Value - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jun. 30, 2019
Total available-for-sale securities	$ 139,383	$ 144,010
US Treasury Securities [Member]
Total available-for-sale securities	1,761
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Total available-for-sale securities
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Total available-for-sale securities	1,761
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Total available-for-sale securities
US Government-sponsored Enterprises Debt Securities [Member]
Total available-for-sale securities	10,864	19,513
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Total available-for-sale securities
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Total available-for-sale securities	10,864	19,513
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Total available-for-sale securities
US States and Political Subdivisions Debt Securities [Member]
Total available-for-sale securities	58,933	57,929
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Total available-for-sale securities
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Total available-for-sale securities	58,933	57,929
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Total available-for-sale securities
Residential Mortgage Backed Securities [Member]
Total available-for-sale securities	57,069	56,311
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Total available-for-sale securities
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Total available-for-sale securities	57,069	56,311
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Total available-for-sale securities
Collateralized Debt Obligations [Member]
Total available-for-sale securities	9,353	10,257
Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Total available-for-sale securities
Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Total available-for-sale securities	9,353	10,257
Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Total available-for-sale securities
Commercial Mortgage Backed Securities [Member]
Total available-for-sale securities	1,403
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Total available-for-sale securities
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Total available-for-sale securities	1,403
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Total available-for-sale securities