v3.26.3
INVESTMENT SECURITIES - Schedule of Available-for-Sale and Held-to-Maturity Investment Securities with Unrealized Losses by Aggregated Major Security Type and Length of Time in Continuous Unrealized Loss Position (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value $ 6,821,942 $ 341,118
Available-for-Sale, Less than 12 months, Unrealized Losses (300,650) (1,136)
Available-for-Sale, 12 months or longer, Fair Value 4,222,405 4,885,808
Available-for-Sale, 12 months or longer, Unrealized Losses (839,085) (653,197)
Available-for-Sale, Fair Value 11,044,347 5,226,926
Available-for-Sale, Unrealized Losses (1,139,735) (654,333)
U.S. Treasury    
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value 18,852 0
Available-for-Sale, Less than 12 months, Unrealized Losses (101) 0
Available-for-Sale, 12 months or longer, Fair Value 172,734 184,175
Available-for-Sale, 12 months or longer, Unrealized Losses (10,178) (7,615)
Available-for-Sale, Fair Value 191,586 184,175
Available-for-Sale, Unrealized Losses (10,279) (7,615)
U.S. government-sponsored entities and agencies    
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value 206,514 79,916
Available-for-Sale, Less than 12 months, Unrealized Losses (10,755) (78)
Available-for-Sale, 12 months or longer, Fair Value 1,087,591 1,173,044
Available-for-Sale, 12 months or longer, Unrealized Losses (164,231) (134,717)
Available-for-Sale, Fair Value 1,294,105 1,252,960
Available-for-Sale, Unrealized Losses (174,986) (134,795)
Mortgage-backed securities - Agency    
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value 6,482,292 252,875
Available-for-Sale, Less than 12 months, Unrealized Losses (285,437) (953)
Available-for-Sale, 12 months or longer, Fair Value 2,739,227 3,157,476
Available-for-Sale, 12 months or longer, Unrealized Losses (628,687) (486,252)
Available-for-Sale, Fair Value 9,221,519 3,410,351
Available-for-Sale, Unrealized Losses (914,124) (487,205)
States and political subdivisions    
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value 100,902 6,561
Available-for-Sale, Less than 12 months, Unrealized Losses (3,983) (17)
Available-for-Sale, 12 months or longer, Fair Value 125,661 234,389
Available-for-Sale, 12 months or longer, Unrealized Losses (29,026) (17,269)
Available-for-Sale, Fair Value 226,563 240,950
Available-for-Sale, Unrealized Losses (33,009) (17,286)
Pooled trust preferred securities    
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value 0 0
Available-for-Sale, Less than 12 months, Unrealized Losses 0 0
Available-for-Sale, 12 months or longer, Fair Value 12,987 11,734
Available-for-Sale, 12 months or longer, Unrealized Losses (843) (2,085)
Available-for-Sale, Fair Value 12,987 11,734
Available-for-Sale, Unrealized Losses (843) (2,085)
Other securities    
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value 13,382 1,766
Available-for-Sale, Less than 12 months, Unrealized Losses (374) (88)
Available-for-Sale, 12 months or longer, Fair Value 84,205 124,990
Available-for-Sale, 12 months or longer, Unrealized Losses (6,120) (5,259)
Available-for-Sale, Fair Value 97,587 126,756
Available-for-Sale, Unrealized Losses $ (6,494) $ (5,347)