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INVESTMENT SECURITIES - Unrealized Gain/Loss on Investment (Details) - USD ($) $ in Thousands | Sep. 30, 2022 | Dec. 31, 2021
--- | --- | ---
AFS |  |
Amortized cost | $ 1,427,111 | $ 975,763
Gross unrealized gains | 138 | 30,084
Gross unrealized losses | (139,522) | (3,325)
Fair value | 1,287,727 | 1,002,522
Residential mortgage-backed securities |  |
AFS |  |
Amortized cost | 208,807 | 32,905
Gross unrealized gains | 0 | 396
Gross unrealized losses | (9,817) | (338)
Fair value | 198,990 | 32,963
Commercial mortgage-backed securities |  |
AFS |  |
Amortized cost | 68,706 | 62,094
Gross unrealized gains | 0 | 933
Gross unrealized losses | (9,834) | (235)
Fair value | 58,872 | 62,792
Residential collateralized mortgage obligations |  |
AFS |  |
Amortized cost | 489,223 | 186,703
Gross unrealized gains | 12 | 2,012
Gross unrealized losses | (36,021) | (1,321)
Fair value | 453,214 | 187,394
Commercial collateralized mortgage obligations |  |
AFS |  |
Amortized cost | 97,886 | 135,102
Gross unrealized gains | 0 | 1,890
Gross unrealized losses | (7,025) | (333)
Fair value | 90,861 | 136,659
Municipal bonds |  |
AFS |  |
Amortized cost | 498,665 | 516,693
Gross unrealized gains | 121 | 24,154
Gross unrealized losses | (70,589) | (924)
Fair value | 428,197 | 539,923
HTM |  |
Amortized cost | 3,099 | 4,169
Gross unrealized gains | 0 | 136
Gross unrealized losses | (101) | 0
Fair value | 2,998 | 4,305
Corporate debt securities |  |
AFS |  |
Amortized cost | 36,733 | 18,918
Gross unrealized gains | 0 | 699
Gross unrealized losses | (2,971) | (1)
Fair value | 33,762 | 19,616
U.S. Treasury securities |  |
AFS |  |
Amortized cost | 23,092 | 23,348
Gross unrealized gains | 0 | 0
Gross unrealized losses | (3,265) | (173)
Fair value | 19,827 | $ 23,175
Agency debentures |  |
AFS |  |
Amortized cost | 3,999 |
Gross unrealized gains | 5 |
Gross unrealized losses | 0 |
Fair value | $ 4,004 |

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