Note 4 - Loans and Allowance for Loan Losses - Loans Individually Evaluated for Impairment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Allowance for Loan Losses Allocated	$ 261		$ 98
Unpaid principal balance	22,226		14,376
Recorded investment	20,472		12,618
Average impaired loans	15,428	$ 16,606
Interest income recognized	302	204
Cash basis interest recognized	302	204
Residential Portfolio Segment [Member]
Unpaid principal balance - with allowance recorded	1,295
Recorded investment - with allowance recorded	1,295
Allowance for Loan Losses Allocated	89
Unpaid principal balance - with no allowance recorded	450		1,667
Recorded investment - with no allowance recorded	450		1,667
Average impaired loans - with allowance recorded	1,255	1,550
Interest income recognized - with allowance recorded	7	20
Cash basis interest recognized - with allowance recorded	7	20
Average impaired loans - with no allowance recorded	451
Interest income recognized - with no allowance recorded	4
Cash basis interest recognized - with no allowance recorded	4
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Unpaid principal balance - with no allowance recorded	3,356
Recorded investment - with no allowance recorded	3,356
Average impaired loans - with no allowance recorded	2,862
Interest income recognized - with no allowance recorded	52
Cash basis interest recognized - with no allowance recorded	52
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Unpaid principal balance - with allowance recorded	358		362
Recorded investment - with allowance recorded	358		362
Allowance for Loan Losses Allocated	95		98
Unpaid principal balance - with no allowance recorded	8,830		2,368
Recorded investment - with no allowance recorded	7,408		946
Average impaired loans - with allowance recorded	360	371
Interest income recognized - with allowance recorded		1
Cash basis interest recognized - with allowance recorded		1
Average impaired loans - with no allowance recorded	4,177	3,521
Interest income recognized - with no allowance recorded	112	20
Cash basis interest recognized - with no allowance recorded	112	20
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Unpaid principal balance - with allowance recorded	156		2,527
Recorded investment - with allowance recorded	156		2,527
Allowance for Loan Losses Allocated
Average impaired loans - with allowance recorded	78	2,491
Interest income recognized - with allowance recorded	2
Cash basis interest recognized - with allowance recorded	2	34
Interest income recognized - with no allowance recorded		34
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Unpaid principal balance - with no allowance recorded	332		336
Recorded investment - with no allowance recorded
Average impaired loans - with no allowance recorded
Interest income recognized - with no allowance recorded	5	5
Cash basis interest recognized - with no allowance recorded	5	5
Commercial and Industrial Portfolio Segment [Member]
Unpaid principal balance - with allowance recorded	1,968		7,116
Recorded investment - with allowance recorded	1,968		$ 7,116
Allowance for Loan Losses Allocated	71
Unpaid principal balance - with no allowance recorded	5,475
Recorded investment - with no allowance recorded	5,475
Average impaired loans - with allowance recorded	984	8,673
Interest income recognized - with allowance recorded	36
Cash basis interest recognized - with allowance recorded	36	124
Average impaired loans - with no allowance recorded	5,258
Interest income recognized - with no allowance recorded	84	$ 124
Cash basis interest recognized - with no allowance recorded	84
Consumer Portfolio Segment [Member]
Unpaid principal balance - with allowance recorded	6
Recorded investment - with allowance recorded	6
Allowance for Loan Losses Allocated	6
Average impaired loans - with allowance recorded	3
Interest income recognized - with allowance recorded
Cash basis interest recognized - with allowance recorded