| Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] |
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Fair Value Measurements at September 30, 2025 Using
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Quoted Prices in
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Active Markets
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Significant Other
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Significant
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for Identical
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Observable Inputs
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Unobservable
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Assets (Level 1)
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(Level 2)
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Inputs (Level 3)
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Total
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(In Thousands)
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| Assets Measured on a Recurring Basis: |
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Available for sale debt securities:
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|
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U.S. Treasury securities
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$ |
672,566 |
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|
$ |
- |
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|
$ |
- |
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|
$ |
672,566 |
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Mortgage-backed securities
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- |
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|
142,907 |
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|
- |
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|
142,907 |
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State and municipal securities
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- |
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9,735 |
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|
|
- |
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9,735 |
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Corporate debt
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- |
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352,936 |
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- |
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352,936 |
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Total available-for-sale debt securities
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672,566 |
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505,578 |
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- |
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1,178,144 |
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Total assets at fair value
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$ |
672,566 |
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|
$ |
505,578 |
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$ |
- |
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|
$ |
1,178,144 |
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Fair Value Measurements at December 31, 2024 Using
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Quoted Prices in
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Active Markets
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Significant Other
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Significant
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for Identical
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Observable Inputs
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Unobservable
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Assets (Level 1)
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(Level 2)
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Inputs (Level 3)
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Total
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(In Thousands)
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| Assets Measured on a Recurring Basis: |
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Available for sale debt securities:
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|
|
|
|
|
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U.S. Treasury securities
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$ |
617,486 |
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$ |
- |
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$ |
- |
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|
$ |
617,486 |
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Government agency securities
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- |
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- |
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- |
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- |
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Mortgage-backed securities
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- |
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219,274 |
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- |
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219,274 |
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State and municipal securities
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- |
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9,517 |
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- |
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9,517 |
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Corporate debt
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- |
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315,123 |
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- |
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|
315,123 |
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Total available-for-sale debt securities
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617,486 |
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543,914 |
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- |
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1,161,400 |
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Total assets at fair value
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$ |
617,486 |
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|
$ |
543,914 |
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|
$ |
- |
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|
$ |
1,161,400 |
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| Fair Value Measurements, Nonrecurring [Table Text Block] |
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Fair Value Measurements at September 30, 2025
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Quoted Prices in Active Markets for Identical Assets (Level 1)
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Significant Other Observable Inputs (Level 2)
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Significant Unobservable Inputs (Level 3)
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Total
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(In Thousands)
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| Assets Measured on a Nonrecurring Basis: |
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Loans individually evaluated
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$ |
- |
|
|
$ |
- |
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|
$ |
193,508 |
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|
$ |
193,508 |
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Other real estate owned and repossessed assets
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- |
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- |
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|
611 |
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|
611 |
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Total assets at fair value
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$ |
- |
|
|
$ |
- |
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|
$ |
194,119 |
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|
$ |
194,119 |
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Fair Value Measurements at December 31, 2024
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|
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Quoted Prices in Active Markets for Identical Assets (Level 1)
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Significant Other Observable Inputs (Level 2)
|
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Significant Unobservable Inputs (Level 3)
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Total
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(In Thousands) |
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Assets Measured on a Nonrecurring Basis:
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Loans individually evaluated
|
|
$ |
- |
|
|
$ |
- |
|
|
$ |
95,667 |
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|
$ |
95,667 |
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Other real estate owned and repossessed assets
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- |
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|
- |
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2,531 |
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2,531 |
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Total assets at fair value
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$ |
- |
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|
$ |
- |
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|
$ |
98,198 |
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$ |
98,198 |
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| Fair Value, by Balance Sheet Grouping [Table Text Block] |
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September 30, 2025
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Carrying / Notional Amount
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Estimated Fair Value
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Quoted Market Prices in an Active Market (Level 1)
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Models with Significant Observable Market Parameters (Level 2)
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Models with Significant Unobservable Market Parameters (Level 3)
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(In Thousands)
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Financial Assets:
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Cash and cash equivalents
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$ |
1,763,303 |
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$ |
1,763,303 |
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$ |
1,763,303 |
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$ |
- |
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$ |
- |
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Held to maturity U.S. Treasury securities
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249,566 |
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238,131 |
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238,131 |
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- |
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- |
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Federal funds sold
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10,002 |
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10,002 |
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|
- |
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10,002 |
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- |
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Held to maturity debt securities
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421,529 |
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384,194 |
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- |
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384,194 |
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- |
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Mortgage loans held for sale
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9,433 |
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9,433 |
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- |
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9,433 |
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|
- |
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Restricted equity securities
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|
12,203 |
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|
12,203 |
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|
- |
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|
12,203 |
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|
|
- |
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Held to maturity debt securities
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|
500 |
|
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|
500 |
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|
|
- |
|
|
|
- |
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|
500 |
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Loans, net
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13,141,732 |
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12,885,745 |
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|
- |
|
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|
- |
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12,885,745 |
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Financial Liabilities:
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|
|
|
|
|
|
|
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Deposits
|
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$ |
14,106,922 |
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$ |
14,105,877 |
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|
$ |
- |
|
|
$ |
14,105,877 |
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|
$ |
- |
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Federal funds purchased
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|
1,488,150 |
|
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|
1,488,150 |
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|
- |
|
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1,488,150 |
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|
- |
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Other borrowings
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|
64,750 |
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|
59,956 |
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|
|
- |
|
|
|
59,956 |
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|
|
- |
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December 31, 2024
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Carrying / Notional Amount
|
|
|
Estimated Fair Value
|
|
|
Quoted Market Prices in an Active Market (Level 1)
|
|
|
Models with Significant Observable Market Parameters (Level 2)
|
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|
Models with Significant Unobservable Market Parameters (Level 3)
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(In Thousands)
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Financial Assets:
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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Cash and cash equivalents
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|
$ |
2,375,589 |
|
|
$ |
2,375,589 |
|
|
$ |
2,375,589 |
|
|
$ |
- |
|
|
$ |
- |
|
|
Held to maturity U.S. Treasury securities
|
|
|
249,403 |
|
|
|
229,771 |
|
|
|
229,771 |
|
|
|
- |
|
|
|
- |
|
|
Federal funds sold
|
|
|
1,045 |
|
|
|
1,045 |
|
|
|
- |
|
|
|
1,045 |
|
|
|
- |
|
|
Held to maturity debt securities
|
|
|
465,200 |
|
|
|
409,475 |
|
|
|
- |
|
|
|
409,475 |
|
|
|
- |
|
|
Mortgage loans held for sale
|
|
|
9,211 |
|
|
|
9,211 |
|
|
|
- |
|
|
|
9,211 |
|
|
|
- |
|
|
Restricted equity securities
|
|
|
11,300 |
|
|
|
11,300 |
|
|
|
- |
|
|
|
11,300 |
|
|
|
- |
|
|
Held to maturity debt securities
|
|
|
250 |
|
|
|
250 |
|
|
|
- |
|
|
|
- |
|
|
|
250 |
|
|
Loans, net
|
|
|
12,441,378 |
|
|
|
12,013,721 |
|
|
|
- |
|
|
|
- |
|
|
|
12,013,721 |
|
|
Financial Liabilities:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Deposits
|
|
$ |
13,543,459 |
|
|
$ |
13,540,438 |
|
|
$ |
- |
|
|
$ |
13,540,438 |
|
|
$ |
- |
|
|
Federal funds purchased
|
|
|
1,993,728 |
|
|
|
1,993,728 |
|
|
|
- |
|
|
|
1,993,728 |
|
|
|
- |
|
|
Other borrowings
|
|
|
64,743 |
|
|
|
59,130 |
|
|
|
- |
|
|
|
59,130 |
|
|
|
- |
|
|