Note 1 - Summary of Significant Accounting Policies - Impact of Adoption of Accounting Policy (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Allowance for credit losses on loans		$ 51,920	$ 36,647	$ 26,791
Total allowance for credit losses on off-balance sheet exposures			3,850	350
Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		9,856
Total allowance for credit losses on off-balance sheet exposures	[1]		3,500
Home Equity Line of Credit [Member]
Allowance for credit losses on loans		895	842	728
Home Equity Line of Credit [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		114
Commercial Real Estate Portfolio Segment [Member]
Allowance for credit losses on loans		26,379	14,552	8,562
Commercial Real Estate Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		5,990
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member]
Allowance for credit losses on loans		19,396	8,333	5,235
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		3,098
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied [Member]
Allowance for credit losses on loans		6,983	6,219	3,327
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		2,892
Commercial and Industrial Portfolio Segment [Member] | Term, Excluding PPP [Member]
Allowance for credit losses on loans			7,147	6,782
Commercial and Industrial Portfolio Segment [Member] | Term, Excluding PPP [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		365
Commercial and Industrial Portfolio Segment [Member] | Lines of Credit [Member]
Allowance for credit losses on loans		3,614	4,129	5,657
Commercial and Industrial Portfolio Segment [Member] | Lines of Credit [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		(1,528)
Total Commercial and Industrial Portfolio Segment [Member]
Allowance for credit losses on loans		12,584	11,276	12,439
Total Commercial and Industrial Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		(1,163)
Residential Real Estate Portfolio Segment [Member]
Allowance for credit losses on loans		5,207	4,089	2,474
Residential Real Estate Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		1,615
Residential Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member]
Allowance for credit losses on loans		1,818	1,376	947
Residential Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		429
Residential Real Estate Portfolio Segment [Member] | Owner Occupied [Member]
Allowance for credit losses on loans		3,389	2,713	1,527
Residential Real Estate Portfolio Segment [Member] | Owner Occupied [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		1,186
Construction and Development [Member]
Allowance for credit losses on loans		6,119	5,161	2,105
Construction and Development [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		3,056
Consumer Portfolio Segment [Member]
Allowance for credit losses on loans		340	398	100
Consumer Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		298
Finance Leases Portfolio Segment [Member]
Allowance for credit losses on loans		$ 261	233	237
Finance Leases Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		(4)
Commercial Portfolio Segment [Member]
Allowance for credit losses on loans			96	$ 146
Commercial Portfolio Segment [Member] | Accounting Standards Update 2016-13 [Member]
Allowance for credit losses on loans	[1]		$ (50)

[1] The impact of the ASC 326 adoption on the ACL on loans reflects $8.2 million related to the transition from the incurred loss ACL model to the CECL ACL model and $1.6 million related to the transition from PCI to PCD methodology as defined in thestandard.