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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Note 5 - Loans Receivable and Related Allowance for Loan Losses - Summary of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Loans, gross	$ 598,485		$ 583,361
Allowance for loan losses	6,360	$ 6,118	6,127	$ 5,940	$ 5,767	$ 5,545
Total loans, net	592,125		577,234
Mortgage Receivable [Member]
Loans, gross	536,943		514,831
Other Loans [Member]
Loans, gross	61,542		68,530
Residential Portfolio Segment [Member]
Loans, gross	237,106		221,823
Allowance for loan losses	2,161	2,033	2,090	2,038	1,994	1,846
Residential Portfolio Segment [Member] \| Mortgage Receivable [Member]
Loans, gross	237,106		221,823
Home Equity Loans and Lines of Credit [Member]
Loans, gross	99,668		99,940
Allowance for loan losses	659	650	646	627	639	633
Home Equity Loans and Lines of Credit [Member] \| Mortgage Receivable [Member]
Loans, gross	99,668		99,940
Commercial Real Estate Portfolio Segment [Member]
Loans, gross	200,169		193,068
Allowance for loan losses	2,970	2,882	2,753	2,626	2,460	2,314
Commercial Real Estate Portfolio Segment [Member] \| Mortgage Receivable [Member]
Loans, gross	200,169		193,068
Commercial Portfolio Segment [Member]
Loans, gross	52,594		58,941
Allowance for loan losses	510	499	585	596	621	700
Commercial Portfolio Segment [Member] \| Other Loans [Member]
Loans, gross	52,594		58,941
Consumer Portfolio Segment [Member]
Loans, gross	8,948		9,589
Allowance for loan losses	60	$ 54	53	$ 53	$ 53	$ 52
Consumer Portfolio Segment [Member] \| Other Loans [Member]
Loans, gross	$ 8,948		$ 9,589