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INVESTMENT SECURITIES - Continuous Unrealized Loss on Investment (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
AFS |  |
AFS, Less than 12 months, Gross unrealized losses | $ (3,526) | $ (95,493)
AFS, Less than 12 months, Fair value | 211,029 | 1,187,577
AFS, Twelve months or more, Gross unrealized losses | (165,423) | (35,604)
AFS, Twelve months or more, Fair value | 1,047,615 | 146,230
AFS, Total, Gross unrealized losses | (168,949) | (131,097)
AFS, Total, Fair value | 1,258,644 | 1,333,807
Residential mortgage-backed securities |  |
AFS |  |
AFS, Less than 12 months, Gross unrealized losses | (37) | (8,845)
AFS, Less than 12 months, Fair value | 1,601 | 191,398
AFS, Twelve months or more, Gross unrealized losses | (15,631) | (1,338)
AFS, Twelve months or more, Fair value | 175,779 | 5,763
AFS, Total, Gross unrealized losses | (15,668) | (10,183)
AFS, Total, Fair value | 177,380 | 197,161
Commercial mortgage-backed securities |  |
AFS |  |
AFS, Less than 12 months, Gross unrealized losses | 0 | (5,729)
AFS, Less than 12 months, Fair value | 63 | 41,416
AFS, Twelve months or more, Gross unrealized losses | (9,918) | (3,633)
AFS, Twelve months or more, Fair value | 47,500 | 14,619
AFS, Total, Gross unrealized losses | (9,918) | (9,362)
AFS, Total, Fair value | 47,563 | 56,035
Residential collateralized mortgage obligations |  |
AFS |  |
AFS, Less than 12 months, Gross unrealized losses | (581) | (27,789)
AFS, Less than 12 months, Fair value | 110,423 | 498,333
AFS, Twelve months or more, Gross unrealized losses | (46,546) | (11,633)
AFS, Twelve months or more, Fair value | 369,133 | 45,689
AFS, Total, Gross unrealized losses | (47,127) | (39,422)
AFS, Total, Fair value | 479,556 | 544,022
Commercial collateralized mortgage obligations |  |
AFS |  |
AFS, Less than 12 months, Gross unrealized losses | (12) | (4,787)
AFS, Less than 12 months, Fair value | 4,045 | 56,671
AFS, Twelve months or more, Gross unrealized losses | (6,922) | (2,603)
AFS, Twelve months or more, Fair value | 54,707 | 13,848
AFS, Total, Gross unrealized losses | (6,934) | (7,390)
AFS, Total, Fair value | 58,752 | 70,519
Municipal bonds |  |
AFS |  |
AFS, Less than 12 months, Gross unrealized losses | (2,397) | (44,513)
AFS, Less than 12 months, Fair value | 30,863 | 350,918
AFS, Twelve months or more, Gross unrealized losses | (74,878) | (13,326)
AFS, Twelve months or more, Fair value | 341,014 | 46,377
AFS, Total, Gross unrealized losses | (77,275) | (57,839)
AFS, Total, Fair value | 371,877 | 397,295
HTM |  |
HFM, Less than 12 months, Gross unrealized losses | 0 | (56)
HFM, Less than 12 months, Fair value | 0 | 2,385
HFM, 12 months or more, Gross unrealized losses | (96) | 0
HFM, 12 months or more, Fair value | 2,293 | 0
HFM, Total, Gross unrealized losses | (96) | (56)
HTM, Total, Fair value | 2,293 | 2,385
Corporate debt securities |  |
AFS |  |
AFS, Less than 12 months, Gross unrealized losses | (44) | (3,801)
AFS, Less than 12 months, Fair value | 9,956 | 32,871
AFS, Twelve months or more, Gross unrealized losses | (6,652) | 0
AFS, Twelve months or more, Fair value | 29,012 | 0
AFS, Total, Gross unrealized losses | (6,696) | (3,801)
AFS, Total, Fair value | 38,968 | 32,871
U.S. Treasury securities |  |
AFS |  |
AFS, Less than 12 months, Gross unrealized losses | 0 | 0
AFS, Less than 12 months, Fair value | 0 | 0
AFS, Twelve months or more, Gross unrealized losses | (3,301) | (3,071)
AFS, Twelve months or more, Fair value | 19,445 | 19,934
AFS, Total, Gross unrealized losses | (3,301) | (3,071)
AFS, Total, Fair value | 19,445 | 19,934
Agency debentures |  |
AFS |  |
AFS, Less than 12 months, Gross unrealized losses | (455) | (29)
AFS, Less than 12 months, Fair value | 54,078 | 15,970
AFS, Twelve months or more, Gross unrealized losses | (1,575) | 0
AFS, Twelve months or more, Fair value | 11,025 | 0
AFS, Total, Gross unrealized losses | (2,030) | (29)
AFS, Total, Fair value | $ 65,103 | $ 15,970

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