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Note 3 - Loans and Allowance for Credit Losses (Details Textual) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024
Financing Receivable, before Allowance for Credit Loss | $ 4,615,160 |  | $ 4,600,781
Increase (Decrease) in Finance Receivables | $ 14,400 |  |
Loans and Leases Receivable, Percentage Period Increase (Decrease) | 0.30% |  |
Financing Receivable, Nonaccrual, Interest Income | $ 500 | $ 500 |
Financing Receivable, Revolving, Converted to Term Loan During Period | 1,300 |  | 9,100
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease) From Forecast Changes | (100) |  | (2,200)
Financing Receivable, Individually Evaluated for Credit Loss | 9,800 |  | 7,400
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment | 6,800 |  | 2,200
Commercial Portfolio Segment [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss | $ 3,750,307 |  | $ 3,707,304
Financing Receivables, Prepayment Speed Assumed | 2.00% |  | 2.00%
Retail Portfolio Segment [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss | $ 864,853 |  | $ 893,477
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss | $ 780,917 |  | $ 827,597
Financing Receivables, Prepayment Speed Assumed | 9.50% |  | 7.80%
Retail Portfolio Segment [Member] | Other Consumer Loans [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss | $ 83,936 |  | $ 65,880
Financing Receivables, Prepayment Speed Assumed | 9.50% |  | 7.80%

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- Definition Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment. + References No definition available. + Details
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- Definition Amount of financing receivable individually evaluated for credit loss. Excludes financing receivable collectively evaluated for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SAB Topic 6.L.5.a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480418/310-10-S99-4 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11C -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-11C + Details
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