Note 3 - Loans Receivable and Related Allowance for Loan Losses - Summary of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total	$ 701,904	$ 715,172
Loans and Leases Receivable, Allowance, Ending Balance	6,556	6,508	$ 6,127
Total loans, net	695,348	708,664
Mortgage Receivable [Member]
Total	620,662	637,891
Other Loans [Member]
Total	81,242	77,281
Residential Portfolio Segment [Member]
Total	293,170	295,405
Loans and Leases Receivable, Allowance, Ending Balance	2,309	2,198	2,090
Residential Portfolio Segment [Member] \| Mortgage Receivable [Member]
Total	293,170	295,405
Home Equity Loans and Lines of Credit [Member]
Total	97,541	103,752
Loans and Leases Receivable, Allowance, Ending Balance	626	648	646
Home Equity Loans and Lines of Credit [Member] \| Mortgage Receivable [Member]
Total	97,541	103,752
Commercial Real Estate Portfolio Segment [Member]
Total	229,951	238,734
Loans and Leases Receivable, Allowance, Ending Balance	2,898	3,106	2,753
Commercial Real Estate Portfolio Segment [Member] \| Mortgage Receivable [Member]
Total	229,951	238,734
Commercial Portfolio Segment [Member]
Total	66,603	66,009
Loans and Leases Receivable, Allowance, Ending Balance	636	500	585
Commercial Portfolio Segment [Member] \| Other Loans [Member]
Total	66,603	66,009
Consumer Portfolio Segment [Member]
Total	14,639	11,272
Loans and Leases Receivable, Allowance, Ending Balance	87	56	$ 53
Consumer Portfolio Segment [Member] \| Other Loans [Member]
Total	$ 14,639	$ 11,272

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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