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Note 18 - Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Equity securities at fair value (Note 2)	$ 2,896	$ 2,851
Securities available for sale (Note 2)	574,787	339,579
US Treasury and Government [Member]
Securities available for sale (Note 2)	2,051	17,215
US Treasury Securities [Member]
Securities available for sale (Note 2)	2,056	2,008
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale (Note 2)	320,368	173,924
Collateralized Mortgage Backed Securities [Member]
Securities available for sale (Note 2)	246,723	142,760
Corporate Debt Securities [Member]
Securities available for sale (Note 2)	2,589	2,672
Trust Preferred Securities [Member]
Securities available for sale (Note 2)	1,000	1,000
Fair Value, Recurring [Member]
Securities available for sale (Note 2)	574,787	339,579
Fair Value, Recurring [Member] | Equity Securities [Member]
Equity securities at fair value (Note 2)	2,896	2,851
Fair Value, Recurring [Member] | US Treasury and Government [Member]
Securities available for sale (Note 2)	2,051	17,215
Fair Value, Recurring [Member] | US Treasury Securities [Member]
Securities available for sale (Note 2)	2,056	2,008
Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Securities available for sale (Note 2)	320,368	173,924
Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]
Securities available for sale (Note 2)	246,723	142,760
Fair Value, Recurring [Member] | Corporate Debt Securities [Member]
Securities available for sale (Note 2)	2,589	2,672
Fair Value, Recurring [Member] | Trust Preferred Securities [Member]
Securities available for sale (Note 2)	1,000	1,000
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Equity Securities [Member]
Equity securities at fair value (Note 2)	1,411	1,379
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US Treasury Securities [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Trust Preferred Securities [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Securities available for sale (Note 2)	563,364	327,212
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Equity Securities [Member]
Equity securities at fair value (Note 2)	0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]
Securities available for sale (Note 2)	2,051	17,215
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Treasury Securities [Member]
Securities available for sale (Note 2)	2,056	2,008
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Securities available for sale (Note 2)	309,945	162,557
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]
Securities available for sale (Note 2)	246,723	142,760
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]
Securities available for sale (Note 2)	2,589	2,672
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Trust Preferred Securities [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Securities available for sale (Note 2)	11,423	12,367
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Equity Securities [Member]
Equity securities at fair value (Note 2)	1,485	1,472
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US Treasury and Government [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US Treasury Securities [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Securities available for sale (Note 2)	10,423	11,367
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Collateralized Mortgage Backed Securities [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Corporate Debt Securities [Member]
Securities available for sale (Note 2)	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Trust Preferred Securities [Member]
Securities available for sale (Note 2)	$ 1,000	$ 1,000

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- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
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-URI http://asc.fasb.org/extlink&oid=121558606&loc=SL82898722-210454

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121553693&loc=d3e26610-111562

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-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27161-111563

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- Definition

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740

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