Note 4 - Loans Receivable and Related Allowance for Loan Losses - Loan Portfolio by Internal Risk Rating (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Loans	$ 706,991	$ 715,172
Residential Portfolio Segment [Member]
Loans	293,903	295,405
Home Equity Loans and Lines of Credit [Member]
Loans	102,553	103,752
Commercial Real Estate Portfolio Segment [Member]
Loans	232,315	238,734
Commercial Portfolio Segment [Member]
Loans	67,317	66,009
Consumer Portfolio Segment [Member]
Loans	10,903	11,272
Not Rated [Member]
Loans	404,504	407,945
Not Rated [Member] | Residential Portfolio Segment [Member]
Loans	291,963	293,919
Not Rated [Member] | Home Equity Loans and Lines of Credit [Member]
Loans	101,766	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	10,775	11,157
Pass [Member]
Loans	281,024	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	216,887	222,335
Pass [Member] | Commercial Portfolio Segment [Member]
Loans	64,137	62,022
Pass [Member] | Consumer Portfolio Segment [Member]
Loans
Special Mention [Member]
Loans	6,253	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	5,741	5,942
Special Mention [Member] | Commercial Portfolio Segment [Member]
Loans	512	542
Special Mention [Member] | Consumer Portfolio Segment [Member]
Loans
Substandard [Member]
Loans	15,210	16,386
Substandard [Member] | Residential Portfolio Segment [Member]
Loans	1,940	1,486
Substandard [Member] | Home Equity Loans and Lines of Credit [Member]
Loans	787	883
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans	9,687	10,457
Substandard [Member] | Commercial Portfolio Segment [Member]
Loans	2,668	3,445
Substandard [Member] | Consumer Portfolio Segment [Member]
Loans	128	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