Note 3 - Loans Receivable and Related Allowance for Loan Losses - Loan Portfolio by Internal Risk Rating (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Loans	$ 701,904	$ 715,172
Residential Portfolio Segment [Member]
Loans	293,170	295,405
Home Equity Loans and Lines of Credit [Member]
Loans	97,541	103,752
Commercial Real Estate Portfolio Segment [Member]
Loans	229,951	238,734
Commercial Portfolio Segment [Member]
Loans	66,603	66,009
Consumer Portfolio Segment [Member]
Loans	14,639	11,272
Not Rated [Member]
Loans	403,487	407,945
Not Rated [Member] | Residential Portfolio Segment [Member]
Loans	291,843	293,919
Not Rated [Member] | Home Equity Loans and Lines of Credit [Member]
Loans	97,087	102,869
Not Rated [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans
Not Rated [Member] | Commercial Portfolio Segment [Member]
Loans
Not Rated [Member] | Consumer Portfolio Segment [Member]
Loans	14,557	11,157
Pass [Member]
Loans	281,380	284,357
Pass [Member] | Residential Portfolio Segment [Member]
Loans
Pass [Member] | Home Equity Loans and Lines of Credit [Member]
Loans
Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans	216,744	222,335
Pass [Member] | Commercial Portfolio Segment [Member]
Loans	64,636	62,022
Pass [Member] | Consumer Portfolio Segment [Member]
Loans
Special Mention [Member]
Loans	5,574	6,484
Special Mention [Member] | Residential Portfolio Segment [Member]
Loans
Special Mention [Member] | Home Equity Loans and Lines of Credit [Member]
Loans
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans	5,370	5,942
Special Mention [Member] | Commercial Portfolio Segment [Member]
Loans	204	542
Special Mention [Member] | Consumer Portfolio Segment [Member]
Loans
Substandard [Member]
Loans	11,463	16,386
Substandard [Member] | Residential Portfolio Segment [Member]
Loans	1,327	1,486
Substandard [Member] | Home Equity Loans and Lines of Credit [Member]
Loans	454	883
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans	7,837	10,457
Substandard [Member] | Commercial Portfolio Segment [Member]
Loans	1,763	3,445
Substandard [Member] | Consumer Portfolio Segment [Member]
Loans	82	115
Doubtful [Member]
Loans
Doubtful [Member] | Residential Portfolio Segment [Member]
Loans
Doubtful [Member] | Home Equity Loans and Lines of Credit [Member]
Loans
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans
Doubtful [Member] | Commercial Portfolio Segment [Member]
Loans
Doubtful [Member] | Consumer Portfolio Segment [Member]
Loans