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Note 2 - Securities - Summary of Amortized Costs and Fair Values of Securities (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Amortized cost, available for sale securities | $ 157,966 | $ 136,355 |
Gross unrealized gains, available for sale securities | 3,014 | 3,952 |
Gross unrealized losses, available for sale securities | (1,238) | (82) |
Fair value, available for sale securities | 159,742 | 140,225 | [1]
Amortized cost, held to maturity securities | 13,424 | 14,234 | [1]
Gross unrealized gains, held to maturity securities | 419 | 509 |
Gross unrealized losses, held to maturity securities |  |  |
Fair value, held to maturity securities | 13,843 | 14,743 | [2]
Amortized cost, total securities | 171,390 | 150,589 |
Gross unrealized gains, total securities | 3,433 | 4,461 |
Gross unrealized losses, total securities | (1,238) | (82) |
Total securities | 173,585 | 154,968 |
US Agency and Mortgage-backed Securities [Member] |  |  |
Amortized cost, available for sale securities | 107,951 | 98,848 |
Gross unrealized gains, available for sale securities | 2,183 | 2,830 |
Gross unrealized losses, available for sale securities | (795) | (80) |
Fair value, available for sale securities | 109,339 | 101,598 |
Amortized cost, held to maturity securities | 8,781 | 9,588 |
Gross unrealized gains, held to maturity securities | 212 | 264 |
Gross unrealized losses, held to maturity securities |  |  |
Fair value, held to maturity securities | 8,993 | 9,852 |
Municipal Bonds [Member] |  |  |
Amortized cost, available for sale securities | 50,015 | 37,507 |
Gross unrealized gains, available for sale securities | 831 | 1,122 |
Gross unrealized losses, available for sale securities | (443) | (2) |
Fair value, available for sale securities | 50,403 | 38,627 |
Amortized cost, held to maturity securities | 3,143 | 3,146 |
Gross unrealized gains, held to maturity securities | 116 | 140 |
Gross unrealized losses, held to maturity securities |  |  |
Fair value, held to maturity securities | 3,259 | 3,286 |
Corporate Debt Securities [Member] |  |  |
Amortized cost, held to maturity securities | 1,500 | 1,500 |
Gross unrealized gains, held to maturity securities | 91 | 105 |
Gross unrealized losses, held to maturity securities |  |  |
Fair value, held to maturity securities | $ 1,591 | $ 1,605 |
[1] | Derived from audited consolidated financial statements.
[2] | Derived from audited consolidated financial statements.

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