v3.25.3
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)