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Investment Securities, Equity Securities with Readily Determinable Fair Values and Other Investments - Contractual Maturities and Estimated Fair Values (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023
Amortized Cost |  |  |
Due in one year or less, held-to-maturity debt securities amortized cost | $ 3,075,000 |  |
Due after one year through five years, held-to-maturity debt securities amortized cost | 1,325,000 |  |
Amortized cost, held-to-maturity debt securities | 4,400,000 | $ 4,400,000 |
Fair Value |  |  |
Due in one year or less, held-to-maturity debt securities, Estimated fair value | 3,075,000 |  |
Due after one year through five years, held-to-maturity debt securities, Estimated fair value | 1,325,000 |  |
Estimated fair value | 4,400,000 | 4,400,000 |
Available-for-sale debt securities amortized cost disclosures |  |  |
Due after five years through ten years, available-for-sale debt securities amortized cost | 2,240,000 |  |
Due after ten years, available-for-sale debt securities amortized cost | 138,837,000 |  |
Residential mortgage-backed securities, available-for-sale debt securities amortized cost | 5,140,013,000 |  |
Amortized cost, Available-for-sale securities | 5,281,090,000 | 5,472,310,000 |
Available for sale debt securities, Estimated Fair Value Disclosures |  |  |
Due after five years through ten years, available-for-sale debt securities, Estimated Fair Value | 2,240,000 |  |
Due after ten years, available-for-sale debt securities, Estimated Fair Value | 133,440,000 |  |
Residential mortgage-backed securities, available-for-sale debt securities, Estimated Fair Value | 4,830,588,000 |  |
Estimated fair value, Available for sale securities | 4,966,268,000 | 4,987,916,000 |
Available for sale debt securities, Estimated Fair Value Disclosures |  |  |
Proceeds from sales and calls of available for sale securities | 15,490,000 | 3,750,000 | $ 2,045,000
Proceeds from sales of mortgage-backed securities | 0 | 0 | 0
Gross gains realized on sales | 0 | 0 | 0
Gross losses realized on sales | 1,000 | $ 1,000 | $ 3,000
Collateral pledged |  |  |
Available-for-sale debt securities amortized cost disclosures |  |  |
Amortized cost, Available-for-sale securities | 1,780,145,000 |  |
Available for sale debt securities, Estimated Fair Value Disclosures |  |  |
Fair value of available for sale investment securities pledged | $ 1,619,467,000 |  |

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