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Securities - Securities with gross unrealized losses (Details) - USD ($) $ in Thousands | Mar. 31, 2026 | Dec. 31, 2025
--- | --- | ---
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | $ 323,111 | $ 315,180
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 1,684,138 | 1,732,850
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 14,339 | 1,985
Twelve Months or More | 441,570 | 420,004
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 1,669,898 | 665,711
Twelve Months or More | 2,553,189 | 2,633,067
U.S. Government agencies |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 16,892 | 15,767
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 116,022 | 117,146
Residential mortgage-backed securities issued by U.S. government agencies or sponsored enterprises |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 181,274 | 177,101
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 942,578 | 975,923
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 4,751 | 459
Twelve Months or More | 142,770 | 137,848
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 563,659 | 145,357
Twelve Months or More | 774,259 | 803,407
Residential collateralized mortgage-obligations issued by U.S. government agencies or sponsored enterprises |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 58,553 | 55,232
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 313,553 | 323,874
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 3,122 | 46
Twelve Months or More | 49,755 | 47,059
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 413,837 | 40,399
Twelve Months or More | 267,423 | 278,620
Commercial mortgage-backed securities issued by U.S. government agencies or sponsored enterprises |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 58,228 | 58,332
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 274,391 | 278,579
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 3,447 | 228
Twelve Months or More | 75,197 | 73,814
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 391,493 | 152,299
Twelve Months or More | 395,381 | 423,165
State and municipal obligations |  |
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 2,715 | 572
Twelve Months or More | 148,308 | 134,645
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 131,282 | 43,620
Twelve Months or More | 855,726 | 903,784
Small Business Administration loan-backed securities |  |
Securities Held to Maturity, Gross Unrealized Losses |  |
Twelve Months or More | 8,164 | 8,748
Securities Held to Maturity, Fair Value |  |
Twelve Months or More | 37,594 | 37,328
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 302 | 680
Twelve Months or More | 24,246 | 25,408
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 159,630 | 284,036
Twelve Months or More | 248,694 | 202,322
Corporate securities |  |
Securities Available for Sale, Gross Unrealized Losses |  |
Less Than Twelve Months | 2 |
Twelve Months or More | 1,294 | 1,230
Securities Available for Sale, Fair Value |  |
Less Than Twelve Months | 9,997 |
Twelve Months or More | $ 11,706 | $ 21,769

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