Note 3 - Loans Receivable and Related Allowance for Loan Losses (Details Textual)	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Loans and Leases Receivable, Deferred Income, Total	$ 2,600,000	$ 2,200,000
Loans and Leases Receivable, Allowance, Ending Balance	6,556,000	6,508,000	$ 6,127,000
Financing Receivable, Troubled Debt Restructuring	409,000	394,000
Allowance for Losses Allocated to Loans Classified as TDRS	$ 5,000	$ 12,000
Financing Receivable, Modifications, Number of Contracts		0
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts	0	0
Residential Portfolio Segment [Member]
Loans and Leases Receivable, Allowance, Ending Balance	$ 2,309,000	$ 2,198,000	$ 2,090,000
Financing Receivable, Troubled Debt Restructuring	67,000
Allowance for Losses Allocated to Loans Classified as TDRS	$ 0
Financing Receivable, Modifications, Number of Contracts	1
United American Savings Bank [Member]
Loans and Leases Receivable, Allowance, Ending Balance	$ 0	$ 0