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Note 18 - Long-term Borrowings (Details Textual) - USD ($) $ in Thousands |  |  | 1 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Nov. 01, 2021 | Jan. 07, 2020 | Nov. 30, 2021 | Dec. 31, 2015 | Sep. 30, 2025 | Dec. 31, 2024 | Aug. 31, 2024
Long-Term Federal Home Loan Bank Advances |  |  |  |  | $ 0 | $ 0 |
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available |  |  |  |  | $ 618,100 |  |
Cortland Statutory Trust I [Member] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  |  |  |  | 5.75% | 6.07% |
Maple Leaf Financial Statutory Trust II [Member] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  |  |  |  | 6.10% | 6.42% |
TSEO Statutory Trust I [Member] |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  |  |  |  | 6.00% | 6.32% |
Cortland Acquisition [Member] |  |  |  |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-Term Debt | $ 4,300 |  |  |  |  |  |
Secured Overnight Financing Rate (SOFR) [Member] | Cortland Statutory Trust I [Member] |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 1.45% |  |  |  |  |  |
Secured Overnight Financing Rate (SOFR) [Member] | Maple Leaf Financial Statutory Trust II [Member] |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 1.80% |  |  |  |  |
Secured Overnight Financing Rate (SOFR) [Member] | TSEO Statutory Trust I [Member] |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  | 1.70% |  |  |
Additional Spread Adjustment [Member] | Cortland Statutory Trust I [Member] |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 0.26% |  |  |  |  |  |
Additional Spread Adjustment [Member] | Maple Leaf Financial Statutory Trust II [Member] |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 0.26% |  |  |  |  |
Additional Spread Adjustment [Member] | TSEO Statutory Trust I [Member] |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  | 0.26% |  |  |
Federal Home Loan Bank Advances [Member] |  |  |  |  |  |  |
Debt Instrument, Collateral Amount |  |  |  |  | $ 1,800,000 | $ 1,700,000 |
Subordinated Debt [Member] |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  | $ 75,000 |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  | 3.125% |  |  |  |
Proceeds from Issuance of Debt |  |  | $ 73,800 |  |  |  |
Debt Instrument, Repurchase Amount |  |  |  |  |  |  | $ 3,000
Subordinated Debt [Member] | Secured Overnight Financing Rate (SOFR) [Member] |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 2.20% |  |  |  |

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