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Note 19 - Fair Value Measurements - Balances of Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands | Dec. 31, 2021 | Sep. 30, 2021 | Dec. 31, 2020
--- | --- | --- | ---
Fair value, available for sale securities | $ 289,495 | $ 289,495 | $ 140,225
Fair Value, Recurring [Member] |  |  |
Fair value, available for sale securities | 289,495 |  | 140,225
Derivatives - cash flow hedges | 941 |  | 431
Assets, Fair Value | 290,436 |  | 140,656
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |  |  |
Fair value, available for sale securities | 0 |  | 0
Derivatives - cash flow hedges | 0 |  | 0
Assets, Fair Value | 0 |  | 0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |
Fair value, available for sale securities | 289,495 |  | 140,225
Derivatives - cash flow hedges | 941 |  | 431
Assets, Fair Value | 290,436 |  | 140,656
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] |  |  |
Fair value, available for sale securities | 0 |  | 0
Derivatives - cash flow hedges | 0 |  | 0
Assets, Fair Value | 0 |  | 0
US Treasury Securities [Member] |  |  |
Fair value, available for sale securities |  | 39,658 |
US Treasury Securities [Member] | Fair Value, Recurring [Member] |  |  |
Fair value, available for sale securities | 39,658 |  |
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |  |  |
Fair value, available for sale securities | 0 |  |
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |
Fair value, available for sale securities | 39,658 |  |
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] |  |  |
Fair value, available for sale securities | 0 |  |
US Agency and Mortgage-backed Securities [Member] |  |  |
Fair value, available for sale securities |  | $ 176,379 | 101,598
US Agency and Mortgage-backed Securities [Member] | Fair Value, Recurring [Member] |  |  |
Fair value, available for sale securities | 176,379 |  | 101,598
US Agency and Mortgage-backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |  |  |
Fair value, available for sale securities | 0 |  | 0
US Agency and Mortgage-backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |
Fair value, available for sale securities | 176,379 |  | 101,598
US Agency and Mortgage-backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] |  |  |
Fair value, available for sale securities | 0 |  | 0
Municipal Bonds [Member] | Fair Value, Recurring [Member] |  |  |
Fair value, available for sale securities | 71,438 |  | 38,627
Municipal Bonds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |  |  |
Fair value, available for sale securities | 0 |  | 0
Municipal Bonds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |
Fair value, available for sale securities | 71,438 |  | 38,627
Municipal Bonds [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] |  |  |
Fair value, available for sale securities | 0 |  | $ 0
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] |  |  |
Fair value, available for sale securities | 2,020 |  |
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |  |  |
Fair value, available for sale securities | 0 |  |
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |
Fair value, available for sale securities | 2,020 |  |
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] |  |  |
Fair value, available for sale securities | $ 0 |  |

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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
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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 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124258926&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=124260329&loc=d3e26610-111562 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563 + Details
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