Note 4 - Loans Receivable and Allowance for Loan and Lease Losses - Loan Portfolio (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019		Mar. 31, 2019	Dec. 31, 2018
Loans receivable, gross	$ 818,841
Allowance for loan and lease losses	(10,916)	$ (10,115)		$ (7,823)	$ (7,609)
Loans receivable, net	807,925	802,049
Business Activities Loans [Member]
Loans receivable, gross	818,841	812,164	[1]
Allowance for loan and lease losses	(10,916)	(10,115)
Loans receivable, net	807,925
Acquired Loans [Member]
Loans receivable, gross		812,164
Allowance for loan and lease losses		(10,115)
Loans receivable, net		802,049
Commercial Real Estate Portfolio Segment [Member]
Loans receivable, gross	304,492
Allowance for loan and lease losses	(4,150)	(3,789)		(1,862)	(1,866)
Commercial Real Estate Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	304,492	314,414
Allowance for loan and lease losses		(3,789)
Commercial Real Estate Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		314,414
Residential Portfolio Segment [Member]
Loans receivable, gross	171,795
Allowance for loan and lease losses	(1,120)	(1,038)		(1,389)	(1,059)
Residential Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	171,795	175,489
Allowance for loan and lease losses		(1,038)
Residential Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		175,489
Commercial Portfolio Segment [Member]
Loans receivable, gross	179,457
Allowance for loan and lease losses	(4,390)	(4,340)		(3,490)	(3,558)
Commercial Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	179,457	173,875
Allowance for loan and lease losses		(4,340)
Commercial Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		173,875
Consumer Portfolio Segment [Member]
Loans receivable, gross	96,620
Allowance for loan and lease losses	(534)	(341)		(592)	(641)
Consumer Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	96,620	85,934
Allowance for loan and lease losses		(341)
Consumer Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		85,934
Construction Portfolio Segment [Member]
Loans receivable, gross	55,255
Allowance for loan and lease losses	(603)	(477)		(355)	(350)
Construction Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	55,255	48,388
Allowance for loan and lease losses		(477)
Construction Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		48,388
Construction to Permanent Portfolio Segment [Member]
Loans receivable, gross	11,222
Allowance for loan and lease losses	(119)	(130)		$ (123)	$ (108)
Construction to Permanent Portfolio Segment [Member] | Business Activities Loans [Member]
Loans receivable, gross	$ 11,222	14,064
Allowance for loan and lease losses		(130)
Construction to Permanent Portfolio Segment [Member] | Acquired Loans [Member]
Loans receivable, gross		$ 14,064

[1]