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DEBT SECURITIES - Schedule of Debt Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Fair Value |  |
Less than 12 months | $ 13,033 | $ 1,070,674
12 months or more | 2,049,784 | 1,368,859
Total | 2,062,817 | 2,439,533
Unrealized Losses |  |
Less than 12 months | (65) | (81,841)
12 months or more | (247,180) | (229,363)
Total | (247,245) | (311,204)
Fair Value |  |
Less than 12 months |  | 58,065
12 months or more | 730,397 | 727,230
Total | 730,397 | 785,295
Unrealized Losses |  |
Less than 12 months |  | (8,009)
12 months or more | (142,231) | (125,008)
Total | (142,231) | (133,017)
U.S. Treasury securities |  |
Fair Value |  |
Less than 12 months | 0 | 74
12 months or more | 15,946 | 113,987
Total | 15,946 | 114,061
Unrealized Losses |  |
Less than 12 months | 0 | 0
12 months or more | (85) | (3,744)
Total | (85) | (3,744)
Obligations of U.S. government corporations and agencies |  |
Fair Value |  |
Less than 12 months | 0 | 19,603
12 months or more | 5,709 | 0
Total | 5,709 | 19,603
Unrealized Losses |  |
Less than 12 months | 0 | (321)
12 months or more | (58) | 0
Total | (58) | (321)
Obligations of states and political subdivisions |  |
Fair Value |  |
Less than 12 months | 11,442 | 166,147
12 months or more | 146,797 | 75,217
Total | 158,239 | 241,364
Unrealized Losses |  |
Less than 12 months | (54) | (10,059)
12 months or more | (17,972) | (16,016)
Total | (18,026) | (26,075)
Asset-backed securities |  |
Fair Value |  |
Less than 12 months | 0 | 390,164
12 months or more | 468,223 | 79,711
Total | 468,223 | 469,875
Unrealized Losses |  |
Less than 12 months | 0 | (15,648)
12 months or more | (1,823) | (4,035)
Total | (1,823) | (19,683)
Commercial mortgage-backed securities |  |
Fair Value |  |
Less than 12 months | 0 | 89,428
12 months or more | 103,509 | 18,966
Total | 103,509 | 108,394
Unrealized Losses |  |
Less than 12 months | 0 | (12,623)
12 months or more | (15,535) | (3,406)
Total | (15,535) | (16,029)
Fair Value |  |
Less than 12 months |  | 58,065
12 months or more | 357,526 | 353,017
Total | 357,526 | 411,082
Unrealized Losses |  |
Less than 12 months |  | (8,009)
12 months or more | (71,000) | (55,729)
Total | (71,000) | (63,738)
Residential mortgage-backed securities |  |
Fair Value |  |
Less than 12 months | 141 | 366,221
12 months or more | 1,110,906 | 876,668
Total | 1,111,047 | 1,242,889
Unrealized Losses |  |
Less than 12 months | (1) | (38,111)
12 months or more | (195,546) | (182,606)
Total | (195,547) | (220,717)
Fair Value |  |
Less than 12 months |  | 0
12 months or more | 372,871 | 374,213
Total | 372,871 | 374,213
Unrealized Losses |  |
Less than 12 months |  | 0
12 months or more | (71,231) | (69,279)
Total | (71,231) | (69,279)
Corporate debt securities |  |
Fair Value |  |
Less than 12 months | 1,450 | 39,037
12 months or more | 198,694 | 204,310
Total | 200,144 | 243,347
Unrealized Losses |  |
Less than 12 months | (10) | (5,079)
12 months or more | (16,161) | (19,556)
Total | $ (16,171) | $ (24,635)

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