Note 15 - Regulatory Capital (Details Textual)	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2019
Scenario, Forecast [Member]
Capital Conservation Buffer Required for Capital Adequacy		2.50%
Savings Bank [Member]
Capital Conservation Buffer	4.70%
Holding Company [Member]
Capital Conservation Buffer	4.60%
Capital Conservation Buffer Required for Capital Adequacy	0.625%
Capital Conservation Buffer Required for Capital Adequacy Annual Increase	0.625%