Note 4 - Loans and Allowance for Credit Losses - Non-accrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Non-accrual with no allowance	$ 2,198
Non-accrual loans	4,235	$ 11,494
Past due 90-days-or-more and still accruing interest	1,762	535
Home Equity Line of Credit [Member]
Non-accrual with no allowance	0
Non-accrual loans	0
Past due 90-days-or-more and still accruing interest	0
Commercial and Industrial Portfolio Segment [Member]
Non-accrual loans		8,202
Past due 90-days-or-more and still accruing interest		0
Commercial and Industrial Portfolio Segment [Member] | Term [Member]
Non-accrual with no allowance	0
Non-accrual loans	0
Past due 90-days-or-more and still accruing interest	203
Commercial and Industrial Portfolio Segment [Member] | Lines of Credit [Member]
Non-accrual with no allowance	0
Non-accrual loans	0
Past due 90-days-or-more and still accruing interest	790
Construction and Development Excluding Undeveloped Land Portfolio Segment [Member]
Non-accrual loans		0
Past due 90-days-or-more and still accruing interest		0
Commercial Real Estate Portfolio Segment [Member]
Non-accrual with no allowance	1,813
Non-accrual loans	3,752
Past due 90-days-or-more and still accruing interest	522
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member]
Non-accrual with no allowance	130
Non-accrual loans	718
Past due 90-days-or-more and still accruing interest	348
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied [Member]
Non-accrual with no allowance	1,683
Non-accrual loans	3,034
Past due 90-days-or-more and still accruing interest	174
Undevelopment Land Portfolio Segment [Member]
Non-accrual loans		0
Past due 90-days-or-more and still accruing interest		0
Real Estate Mortgage Portfolio Segment [Member]
Non-accrual loans		3,292
Past due 90-days-or-more and still accruing interest		535
Real Estate Mortgage Portfolio Segment [Member] | Commercial Investment [Member]
Non-accrual loans		740
Past due 90-days-or-more and still accruing interest		396
Real Estate Mortgage Portfolio Segment [Member] | Owner Occupied Commercial [Member]
Non-accrual loans		2,278
Past due 90-days-or-more and still accruing interest		0
Real Estate Mortgage Portfolio Segment [Member] | One to Four Family Residential [Member]
Non-accrual loans		123
Past due 90-days-or-more and still accruing interest		104
Real Estate Mortgage Portfolio Segment [Member] | Home Equity First Lien [Member]
Non-accrual loans		0
Past due 90-days-or-more and still accruing interest		0
Real Estate Mortgage Portfolio Segment [Member] | Home Equity Junior Lien [Member]
Non-accrual loans		151
Past due 90-days-or-more and still accruing interest		35
Total Commercial and Industrial Portfolio Segment [Member]
Non-accrual with no allowance	0
Non-accrual loans	0
Past due 90-days-or-more and still accruing interest	993
Residential Real Estate Portfolio Segment [Member]
Non-accrual with no allowance	385
Non-accrual loans	483
Past due 90-days-or-more and still accruing interest	198
Residential Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member]
Non-accrual with no allowance	63
Non-accrual loans	63
Past due 90-days-or-more and still accruing interest	103
Residential Real Estate Portfolio Segment [Member] | Owner Occupied [Member]
Non-accrual with no allowance	322
Non-accrual loans	420
Past due 90-days-or-more and still accruing interest	95
Consumer Portfolio Segment [Member]
Non-accrual with no allowance	0
Non-accrual loans	0	0
Past due 90-days-or-more and still accruing interest	0	$ 0
Construction and Development [Member]
Non-accrual with no allowance	0
Non-accrual loans	0
Past due 90-days-or-more and still accruing interest	49
Finance Leases Portfolio Segment [Member]
Non-accrual with no allowance	0
Non-accrual loans	0
Past due 90-days-or-more and still accruing interest	0
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member]
Non-accrual with no allowance	0
Non-accrual loans	0
Past due 90-days-or-more and still accruing interest	$ 0