Note 4 - Loan Receivable and Allowance for Loan and Lease Losses - Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Loans receivable, gross	$ 812,164
Allowance for loan and lease losses	(10,115)	$ (7,609)		$ (6,297)	$ (4,675)
Loans receivable, net	802,049	772,767
Business Activities Loans [Member]
Loans receivable, gross	812,164	780,376	[1]
Allowance for loan and lease losses	(10,115)	(7,609)
Loans receivable, net	802,049
Acquired Loans [Member]
Loans receivable, gross		780,376
Allowance for loan and lease losses		(7,609)
Loans receivable, net		772,767
Commercial Real Estate Portfolio Segment [Member]
Loans receivable, gross	314,414
Allowance for loan and lease losses	(3,789)	(1,866)		(2,212)	(1,853)
Commercial Real Estate Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	314,414	274,938
Allowance for loan and lease losses		(1,866)
Commercial Real Estate Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		274,938
Residential Portfolio Segment [Member]
Loans receivable, gross	175,489
Allowance for loan and lease losses	(1,038)	(1,059)		(959)	(534)
Residential Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	175,489	157,300
Allowance for loan and lease losses		(1,059)
Residential Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		157,300
Commercial Portfolio Segment [Member]
Loans receivable, gross	173,875
Allowance for loan and lease losses	(4,340)	(3,558)		(2,023)	(740)
Commercial Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	173,875	191,852
Allowance for loan and lease losses		(3,558)
Commercial Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		191,852
Consumer Portfolio Segment [Member]
Loans receivable, gross	85,934
Allowance for loan and lease losses	(341)	(641)		(568)	(641)
Consumer Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	85,934	94,569
Allowance for loan and lease losses		(641)
Consumer Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		94,569
Construction Portfolio Segment [Member]
Loans receivable, gross	48,388
Allowance for loan and lease losses	(477)	(350)		(481)	(712)
Construction Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	48,388	46,040
Allowance for loan and lease losses		(350)
Construction Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		46,040
Construction to Permanent Portfolio Segment [Member]
Loans receivable, gross	14,064
Allowance for loan and lease losses	(130)	(108)		$ (54)	$ (69)
Construction to Permanent Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	$ 14,064	15,677
Allowance for loan and lease losses		(108)
Construction to Permanent Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		$ 15,677

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