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Investment Securities (Details) - USD ($) $ in Thousands | Apr. 01, 2021 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Investment securities available-for-sale |  |  |
Amortized Cost |  | $ 849,567 | $ 860,258
Unrealized Gains |  | 21 | 5,362
Unrealized Losses |  | (132,264) | (11,971)
Fair Value |  | 717,324 | 853,649
Amortized Cost |  | 321,902 | 352,061
Unrealized Gains |  |  | 1,110
Unrealized Losses |  | (50,990) | (3,494)
Fair Value |  | 270,912 | 349,677
Amortized Cost |  | 1,171,469 | 1,212,319
Unrealized Gains |  | 21 | 6,472
Unrealized Losses |  | (183,254) | (15,465)
Fair Value |  | 988,236 | 1,203,326
U.S. treasury and government agencies |  |  |
Investment securities available-for-sale |  |  |
Amortized Cost |  | 3,518 | 5,028
Unrealized Gains |  | 19 | 75
Unrealized Losses |  | (17) |
Fair Value |  | 3,520 | 5,103
Mortgage backed securities - Residential agency |  |  |
Investment securities available-for-sale |  |  |
Amortized Cost |  | 705,845 | 717,781
Unrealized Gains |  | 2 | 1,213
Unrealized Losses |  | (118,168) | (11,837)
Fair Value |  | 587,679 | 707,157
Amortized Cost |  | 184,115 | 207,518
Unrealized Losses |  | (33,254) | (3,145)
Fair Value |  | 150,861 | 204,373
Mortgage backed securities - Commercial |  |  |
Investment securities available-for-sale |  |  |
Amortized Cost |  | 70,669 | 88,362
Unrealized Gains |  |  | 2,674
Unrealized Losses |  | (7,111) | (123)
Fair Value |  | 63,558 | 90,913
Asset backed securities |  |  |
Investment securities available-for-sale |  |  |
Amortized Cost |  | 34 | 52
Unrealized Gains |  |  | 2
Fair Value |  | 34 | 54
Corporate bonds |  |  |
Investment securities available-for-sale |  |  |
Amortized Cost |  | 69,501 | 49,035
Unrealized Gains |  |  | 1,398
Unrealized Losses |  | (6,968) | (11)
Fair Value |  | 62,533 | 50,422
Obligations of state and political agencies. |  |  |
Investment securities available-for-sale |  |  |
Amortized Cost |  |  | 144,543
Unrealized Gains |  |  | 1,110
Unrealized Losses |  |  | (349)
Fair Value |  |  | $ 145,304
Amortized Cost |  | 137,787 |
Unrealized Losses |  | (17,736) |
Fair Value |  | $ 120,051 |
Fair value of debt securities available-for-sale transferred to held-to-maturity | $ 149,200 |  |
Net unrealized gain from available-for-sale to held-to-maturity | $ 1,300 |  |

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