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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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