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Note 6 - Loans and Allowance for Credit Losses (Details Textual) - USD ($) $ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 21, 2024 | Dec. 31, 2021
Financing Receivable, Unamortized Loan Cost (Fee) | $ 1,100 |  | $ 200 |  |  |  |
Interest Receivable | 20,075 |  | 15,700 |  |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss | 3,992,534 |  | 2,759,583 |  |  |  |
Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal) | (81,000) |  | 2,200 |  |  |  |
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Credit Loss Expense (Reversal) | 133 |  | 40 |  |  |  |
Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest | 59,929 |  | 35,843 |  | $ 31,146 |  | $ 31,572
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Period Increase (Decrease) | $ 24,100 |  |  |  |  |  |
Percentage of Increase in Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest | 67.20% |  |  |  |  |  |
Financing Receivable, Excluding Accrued Interest, Credit Loss Expense (Reversal) | $ 18,089 | [1] | (225) | [2] | 0 |  |
Loans and Leases Receivables, Impaired, Troubled Debt, Interest Income | 4,800 |  | 500 |  | 200 |  |
Financing Receivable, Nonaccrual, Interest Income | 0 |  | 0 |  | $ 0 |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount |  |  | 0 |  |  |  |
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default | 0 |  | 0 |  |  |  |
Financial Asset, Past Due [Member] |  |  |  |  |  |  |
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount | 0 |  | 0 |  |  |  |
Financial Asset Acquired with Credit Deterioration [Member] |  |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest | 10,200 |  |  |  |  |  |
Financing Receivable, Excluding Accrued Interest, Credit Loss Expense (Reversal) | 7,300 |  |  |  |  |  |
Asset Pledged as Collateral [Member] | FHLB Borrowings, Deposits, and Other [Member] |  |  |  |  |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss | 2,900 |  | 1,600 |  |  |  |
Loans Receivable [Member] |  |  |  |  |  |  |
Interest Receivable | $ 16,400 |  | 12,200 |  |  |  |
Metro Phoenix Bank and HMN Financial Inc. [Member] |  |  |  |  |  |  |
Financing Receivable, Unamortized Purchase Premium (Discount) |  |  | $ 5,100 |  |  | $ 70,600 |
[1] | The difference in the credit loss expense reported herein compared to the consolidated statements of income is associated with the credit loss expense of ($81) million related to off-balance sheet credit exposure and $133 thousand related to investment securities held-to-maturity.
[2] | The difference in the credit loss expense reported herein compared to the consolidated statements of income is associated with the credit loss expense of $44 thousand related to off-balance sheet credit exposure and $46 thousand related to HTM investment securities.

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- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
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