Note 4 - Loans - Average Recorded Investment and Interest Income Recognized on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Average recorded investment	$ 17,915	$ 11,599
Interest income recognized	75	78
Commercial Portfolio Segment [Member]
Average recorded investment	2,021	2,589
Interest income recognized	17	21
Commercial Real Estate Portfolio Segment [Member] | Commercial Non-owner Occupied [Member]
Average recorded investment	8,412	802
Interest income recognized	11	11
Residential Portfolio Segment [Member] | Individual Tax Identification Number Loan [Member]
Average recorded investment	6,874	7,425
Interest income recognized	42	41
Residential Portfolio Segment [Member] | Real Estate Loan [Member] | Mortgage Receivable [Member]
Average recorded investment	184	326
Interest income recognized
Residential Portfolio Segment [Member] | Home Equity Loan [Member]
Average recorded investment	401	422
Interest income recognized	5	5
Consumer Portfolio Segment [Member]
Average recorded investment	23	35
Interest income recognized