XML 47 R40.htm IDEA: XBRL DOCUMENT v3.25.3
Investment Securities - Summary of Continuous Unrealized Loss Position of Securities (Detail) - USD ($)
$ in Thousands
Sep. 30, 2025
Dec. 31, 2024
Schedule of Investments [Line Items]    
Fair Value, Less Than 12 Months, Available-for-sale $ 222,967 $ 207,644
Gross Unrealized Holding Losses, Less Than 12 Months, Available-for-sale (957) (855)
Fair Value, 12 Months or Longer, Available-for-sale 1,986,516 2,124,849
Gross Unrealized Holding Losses, 12 Months or Longer, Available-for-sale (335,877) (447,326)
Fair Value, Available-for-sale 2,209,483 2,332,493
Gross Unrealized Holding Losses, Available-for-sale (336,834) (448,181)
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value 63,223 65,740
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity (1,224) (1,109)
Fair Value, 12 Months or Longer, Held-to-maturity 1,777,987 1,811,354
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity (361,649) (425,372)
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value 1,841,210 1,877,094
Gross Unrealized Holding Losses, Held-to-maturity (362,874) (426,481)
CMO/REMIC [Member]    
Schedule of Investments [Line Items]    
Fair Value, Less Than 12 Months, Available-for-sale 30,549 1
Gross Unrealized Holding Losses, Less Than 12 Months, Available-for-sale  
Fair Value, 12 Months or Longer, Available-for-sale 346,830 351,521
Gross Unrealized Holding Losses, 12 Months or Longer, Available-for-sale (111,026) (120,399)
Fair Value, Available-for-sale 377,379 351,522
Gross Unrealized Holding Losses, Available-for-sale (111,026) (120,399)
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value  
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity  
Fair Value, 12 Months or Longer, Held-to-maturity 602,831 613,937
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity (157,362) (170,121)
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value 602,831 613,937
Gross Unrealized Holding Losses, Held-to-maturity (157,362) (170,121)
Mortgage-backed Securities [Member]    
Schedule of Investments [Line Items]    
Fair Value, Less Than 12 Months, Available-for-sale 192,418 204,428
Gross Unrealized Holding Losses, Less Than 12 Months, Available-for-sale (957) (700)
Fair Value, 12 Months or Longer, Available-for-sale 1,621,368 1,757,066
Gross Unrealized Holding Losses, 12 Months or Longer, Available-for-sale (224,242) (325,677)
Fair Value, Available-for-sale 1,813,786 1,961,494
Gross Unrealized Holding Losses, Available-for-sale (225,199) (326,377)
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value 1,826 2,072
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity 0 (42)
Fair Value, 12 Months or Longer, Held-to-maturity 463,805 502,292
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity (87,814) (109,978)
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value 465,631 504,364
Gross Unrealized Holding Losses, Held-to-maturity (87,814) (110,020)
Municipal Bonds [Member]    
Schedule of Investments [Line Items]    
Fair Value, Less Than 12 Months, Available-for-sale   3,215
Gross Unrealized Holding Losses, Less Than 12 Months, Available-for-sale   (155)
Fair Value, 12 Months or Longer, Available-for-sale 18,318 16,262
Gross Unrealized Holding Losses, 12 Months or Longer, Available-for-sale (609) (1,250)
Fair Value, Available-for-sale 18,318 19,477
Gross Unrealized Holding Losses, Available-for-sale (609) (1,405)
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value 61,397 63,668
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity (1,224) (1,067)
Fair Value, 12 Months or Longer, Held-to-maturity 294,987 286,868
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity (30,378) (38,958)
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value 356,384 350,536
Gross Unrealized Holding Losses, Held-to-maturity (31,602) (40,025)
Government Agency/GSE [Member]    
Schedule of Investments [Line Items]    
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value  
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity  
Fair Value, 12 Months or Longer, Held-to-maturity 416,364 408,257
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity (86,096) (106,315)
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Fair Value 416,364 408,257
Gross Unrealized Holding Losses, Held-to-maturity $ (86,096) $ (106,315)