Note 4 - Allowance for Loan Losses and the Recorded Investment of Loans Based On Impairment Method (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Residential Portfolio Segment [Member]
Individually evaluated for impairment
Collectively evaluated for impairment	906		1,087
Total ending allowance balance	906	$ 1,185	1,087	$ 1,230	$ 1,465	$ 1,426
Loans individually evaluated for impairment	726		1,001
Loans collectively evaluated for impairment	225,005		222,874
Total ending loans balance	225,731		223,875
Commercial Real Estate Portfolio Segment [Member]
Individually evaluated for impairment	1,893		311
Collectively evaluated for impairment	1,571		1,648
Total ending allowance balance	3,464	1,995	1,959	2,795	4,210	4,195
Loans individually evaluated for impairment	11,914		7,318
Loans collectively evaluated for impairment	172,322		161,994
Total ending loans balance	184,236		169,312
Commercial and Industrial Portfolio Segment [Member]
Individually evaluated for impairment	735		1,850
Collectively evaluated for impairment	681		739
Total ending allowance balance	1,416	2,672	2,589	2,287	1,738	1,602
Loans individually evaluated for impairment	9,329		8,691
Loans collectively evaluated for impairment	74,036		73,245
Total ending loans balance	83,365		81,936
Consumer Portfolio Segment [Member]
Individually evaluated for impairment	2		3
Collectively evaluated for impairment	1,146		1,010
Total ending allowance balance	1,148	1,094	1,013	1,132	907	1,111
Loans individually evaluated for impairment	218		218
Loans collectively evaluated for impairment	109,386		110,411
Total ending loans balance	109,604		110,629
Individually evaluated for impairment	2,630		2,164
Collectively evaluated for impairment	4,304		4,484
Total ending allowance balance	6,934	$ 6,946	6,648	$ 7,444	$ 8,320	$ 8,334
Loans individually evaluated for impairment	22,187		17,228
Loans collectively evaluated for impairment	580,749		568,524
Total ending loans balance	$ 602,936		$ 585,752