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Note 5 - Loans and Allowance for Credit Losses (Details Textual) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | ---
Sep. 30, 2024 | Jun. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023 | Dec. 31, 2023 | Jun. 30, 2023 | Dec. 31, 2022
Financing Receivable, Unamortized Loan Cost (Fee) | $ 601 |  |  | $ 601 |  | $ 248 |  |
Financing Receivable, Accrued Interest, after Allowance for Credit Loss | 13,400 |  |  | 13,400 |  | 12,200 |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss | 3,032,343 |  |  | 3,032,343 |  | 2,759,583 |  |
Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal) | 549 |  |  | 31 | $ 44 |  |  |
Debt Securities, Held-to-Maturity, Credit Loss Expense (Reversal) | (14) |  |  | (76) | 46 |  |  |
Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest | 39,142 | $ 38,332 | $ 36,290 | 39,142 | 36,290 | $ 35,843 | $ 35,696 | $ 31,146
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Period Increase (Decrease) |  |  |  | 3,300 |  |  |  |
Percentage of Increase in Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest |  |  |  |  |  | 9.20% |  |
Loans and Leases Receivables, Impaired, Troubled Debt, Interest Income | 1,900 |  | 186 |  |  |  |  |
Financing Receivable, Nonaccrual, Interest Income | 0 |  | 0 |  |  |  |  |
Commercial Borrower [Member] |  |  |  |  |  |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss | 2,122,945 |  |  | 2,122,945 |  | $ 1,849,267 |  |
Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest | 31,165 | 30,980 | $ 26,631 | 31,165 | $ 26,631 | 27,971 | $ 25,582 | $ 23,472
Commercial Borrower [Member] | Commercial Portfolio Segment [Member] |  |  |  |  |  |  |  |
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Period Increase (Decrease) | 4,200 | $ 2,600 |  |  |  |  |  |
Asset Pledged as Collateral [Member] | Deposits [Member] |  |  |  |  |  |  |  |
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss | 2,100,000 |  |  | 2,100,000 |  | 1,600 |  |
Metro Phoenix Bank [Member] |  |  |  |  |  |  |  |
Financing Receivable, Unamortized Purchase Premium (Discount) | $ 3,800 |  |  | $ 3,800 |  | $ 5,100 |  |

X
- Definition The gross interest income that would have been recorded in the period on troubled debt restructurings, if the loans had been current in accordance with their original terms and had been outstanding throughout the period or since origination, if held for part of the period. + References No definition available. + Details
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- Definition Amount of expense (reversal of expense) for expected credit loss 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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