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Investment Securities - Schedule of Available-for-sale Investment Securities Portfolios (Details) - USD ($) | Mar. 31, 2025 | Dec. 31, 2024 | Mar. 31, 2024
--- | --- | --- | ---
Available-for-sale securities |  |  |
Continuous unrealized losses existing for less than 12 months, fair value | $ 1,381,414,000 |  |
Continuous unrealized losses existing for less than 12 months, unrealized losses | (17,185,000) |  |
Continuous unrealized losses existing for greater than 12 months, fair value | 2,475,398,000 |  |
Continuous unrealized losses existing for greater than 12 months, unrealized losses | (495,133,000) |  |
Total, fair value | 3,856,812,000 |  |
Total, unrealized losses | (512,318,000) |  |
Available-for-sale securities, at fair value | 4,220,305,000 | $ 4,141,482,000 | $ 4,387,598,000
U.S. Treasury |  |  |
Available-for-sale securities |  |  |
Continuous unrealized losses existing for less than 12 months, fair value | 0 |  |
Continuous unrealized losses existing for less than 12 months, unrealized losses | 0 |  |
Continuous unrealized losses existing for greater than 12 months, fair value | 0 |  |
Continuous unrealized losses existing for greater than 12 months, unrealized losses | 0 |  |
Total, fair value | 0 |  |
Total, unrealized losses | 0 |  |
Available-for-sale securities, at fair value | 12,994,000 | 37,907,000 | 61,175,000
U.S. government agencies |  |  |
Available-for-sale securities |  |  |
Continuous unrealized losses existing for less than 12 months, fair value | 0 |  |
Continuous unrealized losses existing for less than 12 months, unrealized losses | 0 |  |
Continuous unrealized losses existing for greater than 12 months, fair value | 45,944,000 |  |
Continuous unrealized losses existing for greater than 12 months, unrealized losses | (4,056,000) |  |
Total, fair value | 45,944,000 |  |
Total, unrealized losses | (4,056,000) |  |
Available-for-sale securities, at fair value | 45,944,000 | 44,945,000 | 45,715,000
Municipal |  |  |
Available-for-sale securities |  |  |
Continuous unrealized losses existing for less than 12 months, fair value | 45,437,000 |  |
Continuous unrealized losses existing for less than 12 months, unrealized losses | (717,000) |  |
Continuous unrealized losses existing for greater than 12 months, fair value | 50,975,000 |  |
Continuous unrealized losses existing for greater than 12 months, unrealized losses | (2,867,000) |  |
Total, fair value | 96,412,000 |  |
Total, unrealized losses | (3,584,000) |  |
Available-for-sale securities, at fair value | 188,149,000 | 184,593,000 | 140,590,000
Financial issuers |  |  |
Available-for-sale securities |  |  |
Continuous unrealized losses existing for less than 12 months, fair value | 0 |  |
Continuous unrealized losses existing for less than 12 months, unrealized losses | 0 |  |
Continuous unrealized losses existing for greater than 12 months, fair value | 80,435,000 |  |
Continuous unrealized losses existing for greater than 12 months, unrealized losses | (3,562,000) |  |
Total, fair value | 80,435,000 |  |
Total, unrealized losses | (3,562,000) |  |
Available-for-sale securities, at fair value | 80,435,000 | 80,169,000 | 75,732,000
Other |  |  |
Available-for-sale securities |  |  |
Continuous unrealized losses existing for less than 12 months, fair value | 0 |  |
Continuous unrealized losses existing for less than 12 months, unrealized losses | 0 |  |
Continuous unrealized losses existing for greater than 12 months, fair value | 1,000,000 |  |
Continuous unrealized losses existing for greater than 12 months, unrealized losses | 0 |  |
Total, fair value | 1,000,000 |  |
Total, unrealized losses | 0 |  |
Available-for-sale securities, at fair value | 1,000,000 | 993,000 | 993,000
Residential mortgage-backed securities |  |  |
Available-for-sale securities |  |  |
Continuous unrealized losses existing for less than 12 months, fair value | 1,279,995,000 |  |
Continuous unrealized losses existing for less than 12 months, unrealized losses | (15,142,000) |  |
Continuous unrealized losses existing for greater than 12 months, fair value | 2,224,823,000 |  |
Continuous unrealized losses existing for greater than 12 months, unrealized losses | (467,114,000) |  |
Total, fair value | 3,504,818,000 |  |
Total, unrealized losses | (482,256,000) |  |
Available-for-sale securities, at fair value | 3,586,000,000 | 3,553,638,000 | 3,876,723,000
Commercial (multi-family) mortgage-backed securities |  |  |
Available-for-sale securities |  |  |
Continuous unrealized losses existing for less than 12 months, fair value | 39,068,000 |  |
Continuous unrealized losses existing for less than 12 months, unrealized losses | (1,312,000) |  |
Continuous unrealized losses existing for greater than 12 months, fair value | 6,134,000 |  |
Continuous unrealized losses existing for greater than 12 months, unrealized losses | (384,000) |  |
Total, fair value | 45,202,000 |  |
Total, unrealized losses | (1,696,000) |  |
Available-for-sale securities, at fair value | 56,627,000 | 18,332,000 | 15,676,000
Collateralized mortgage obligations |  |  |
Available-for-sale securities |  |  |
Continuous unrealized losses existing for less than 12 months, fair value | 16,914,000 |  |
Continuous unrealized losses existing for less than 12 months, unrealized losses | (14,000) |  |
Continuous unrealized losses existing for greater than 12 months, fair value | 66,087,000 |  |
Continuous unrealized losses existing for greater than 12 months, unrealized losses | (17,150,000) |  |
Total, fair value | 83,001,000 |  |
Total, unrealized losses | (17,164,000) |  |
Available-for-sale securities, at fair value | 249,156,000 | 220,905,000 | 170,994,000
Mortgage-backed securities, subprime |  |  |
Available-for-sale securities |  |  |
Available-for-sale securities, at fair value | $ 0 | $ 0 | $ 0

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