Note 4 - Investment Securities (Details Textual) Pure in Thousands, $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2026
USD ($)
|
Sep. 30, 2026
USD ($)
|
Sep. 30, 2025
USD ($)
|
Dec. 31, 2025
USD ($)
|
|
| Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss | $ 0 | $ 0 | $ 0 | |
| Debt Securities, Available-for-sale, Holding Greater than 10 Percent of Equity | 0 | 0 | 0 | |
| Proceeds from Sale of Debt Securities, Available-for-Sale | $ 0 | $ 0 | $ 277,477 | |
| Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss | 6,000 | 6,000 | $ 5,200 | |
| Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest | 0 | 0 | 0 | |
| First of Long Island Corporation [Member] | ||||
| Proceeds from Sale of Debt Securities, Available-for-Sale | 277,500 | |||
| Debt Securities, Available-for-Sale, Realized Gain (Loss) | $ 0 | |||
| Asset Pledged as Collateral [Member] | ||||
| Debt Securities, Available-for-Sale, Restricted | $ 624,500 | $ 624,500 | $ 771,200 | |
| X | ||||||||||
- Definition The number of investments in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) that are greater than 10% of equity. No definition available.
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| X | ||||||||||
- Definition Amount, after allowance for credit loss, of accrued interest on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of restricted investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount excluding accrued interest, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Details
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| X | ||||||||||
- Details
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