Note 8 - Loans - Average Balance and Interest Income Recognized Related to Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Average Recorded Investment	$ 80,233	$ 115,085
Interest Income Recognized	698	947
Commercial Portfolio Segment [Member]
Average Recorded Investment	28,316	37,936
Interest Income Recognized	70	256
Real Estate Construction Portfolio Segment [Member]
Average Recorded Investment	4,506	4,815
Interest Income Recognized	98	0
Commercial Real Estate Portfolio Segment [Member]
Average Recorded Investment	36,040	59,070
Interest Income Recognized	459	603
Residential Mortgage and Equity Lines Portfolio Segment [Member]
Average Recorded Investment	11,371	13,264
Interest Income Recognized	$ 71	$ 88

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

Name:	us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration