INVESTMENTS - Age of Gross Unrealized Losses and Associated Fair Value by Investment Category (Details) - USD ($) $ in Thousands |
Sep. 30, 2025 |
Dec. 31, 2024 |
| Investments, Unrealized Loss Position [Line Items] |
|
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months |
$ 165,910
|
$ 620,715
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
682
|
11,525
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer |
1,758,081
|
1,911,161
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
262,860
|
320,809
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position |
1,923,991
|
2,531,876
|
| Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
(263,542)
|
(332,334)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value |
478
|
3,111
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
(1)
|
(33)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value |
58,949
|
63,315
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
(5,763)
|
(7,980)
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value |
59,427
|
66,426
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss |
(5,764)
|
(8,013)
|
| U.S. Treasuries |
|
|
| Investments, Unrealized Loss Position [Line Items] |
|
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months |
0
|
0
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
0
|
0
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer |
94
|
90
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
5
|
9
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position |
94
|
90
|
| Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
(5)
|
(9)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss |
0
|
0
|
| Securities of U.S. government agencies and corporations |
|
|
| Investments, Unrealized Loss Position [Line Items] |
|
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months |
0
|
0
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
0
|
0
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer |
66,433
|
71,678
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
6,771
|
11,546
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position |
66,433
|
71,678
|
| Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
(6,771)
|
(11,546)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss |
0
|
0
|
| Residential Mortgage Backed Securities [Member] |
|
|
| Investments, Unrealized Loss Position [Line Items] |
|
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months |
91,271
|
417,516
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
532
|
9,130
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer |
586,441
|
503,321
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
74,093
|
95,078
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position |
677,712
|
920,837
|
| Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
(74,625)
|
(104,208)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss |
0
|
0
|
| Commercial Mortgage Backed Securities [Member] |
|
|
| Investments, Unrealized Loss Position [Line Items] |
|
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months |
26,320
|
26,516
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
92
|
67
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer |
185,677
|
286,589
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
19,365
|
25,314
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position |
211,997
|
313,105
|
| Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
(19,457)
|
(25,381)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value |
24,507
|
25,990
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
(3,669)
|
(4,454)
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value |
24,507
|
25,990
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss |
(3,669)
|
(4,454)
|
| Collateralized Mortgage Backed Securities [Member] |
|
|
| Investments, Unrealized Loss Position [Line Items] |
|
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months |
7,218
|
120,670
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
15
|
1,776
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer |
292,317
|
296,813
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
38,714
|
50,823
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position |
299,535
|
417,483
|
| Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
(38,729)
|
(52,599)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value |
5,819
|
6,219
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
(530)
|
(788)
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value |
5,819
|
6,219
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss |
(530)
|
(788)
|
| Obligations of state and other political subdivisions |
|
|
| Investments, Unrealized Loss Position [Line Items] |
|
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months |
11,297
|
19,636
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
19
|
351
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer |
459,190
|
478,083
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
102,613
|
109,553
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position |
470,487
|
497,719
|
| Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
(102,632)
|
(109,904)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value |
478
|
3,111
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
(1)
|
(33)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value |
1,250
|
2,288
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
(187)
|
(306)
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value |
1,728
|
5,399
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss |
(188)
|
(339)
|
| Asset-backed Securities [Member] |
|
|
| Investments, Unrealized Loss Position [Line Items] |
|
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months |
26,305
|
26,389
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
23
|
189
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer |
66,899
|
159,135
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
14,059
|
22,190
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position |
93,204
|
185,524
|
| Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
(14,082)
|
(22,379)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss |
0
|
0
|
| Other securities |
|
|
| Investments, Unrealized Loss Position [Line Items] |
|
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months |
3,499
|
9,988
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
1
|
12
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer |
101,030
|
115,452
|
| Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
7,240
|
6,296
|
| Debt Securities, Available-for-Sale, Unrealized Loss Position |
104,529
|
125,440
|
| Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
(7,241)
|
(6,308)
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
0
|
0
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value |
27,373
|
28,818
|
| Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss |
(1,377)
|
(2,432)
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value |
27,373
|
28,818
|
| Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss |
$ (1,377)
|
$ (2,432)
|