Note 3 - Loans Receivable and Related Allowance for Loan Losses - Loan Portfolio by Internal Risk Rating (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans	$ 715,172	$ 583,361
Residential Portfolio Segment [Member]
Loans	295,405	221,823
Home Equity Loans and Lines of Credit [Member]
Loans	103,752	99,940
Commercial Real Estate Portfolio Segment [Member]
Loans	238,734	193,068
Commercial Portfolio Segment [Member]
Loans	66,009	58,941
Consumer Portfolio Segment [Member]
Loans	11,272	9,589
Not Rated [Member]
Loans	407,945	329,119
Not Rated [Member] | Residential Portfolio Segment [Member]
Loans	293,919	220,730
Not Rated [Member] | Home Equity Loans and Lines of Credit [Member]
Loans	102,869	98,946
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	11,157	9,443
Pass [Member]
Loans	284,357	239,420
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	222,335	182,460
Pass [Member] | Commercial Portfolio Segment [Member]
Loans	62,022	56,960
Pass [Member] | Consumer Portfolio Segment [Member]
Loans
Special Mention [Member]
Loans	6,484	3,221
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	5,942	2,744
Special Mention [Member] | Commercial Portfolio Segment [Member]
Loans	542	477
Special Mention [Member] | Consumer Portfolio Segment [Member]
Loans
Substandard [Member]
Loans	16,386	11,601
Substandard [Member] | Residential Portfolio Segment [Member]
Loans	1,486	1,093
Substandard [Member] | Home Equity Loans and Lines of Credit [Member]
Loans	883	994
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans	10,457	7,864
Substandard [Member] | Commercial Portfolio Segment [Member]
Loans	3,445	1,504
Substandard [Member] | Consumer Portfolio Segment [Member]
Loans	115	146
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