v3.26.1
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
Jun. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value $ 3,187,313 $ 341,118
Available-for-Sale, Less than 12 months, Unrealized Losses (31,359) (1,136)
Available-for-Sale, 12 months or longer, Fair Value 4,504,923 4,885,808
Available-for-Sale, 12 months or longer, Unrealized Losses (673,472) (653,197)
Available-for-Sale, Fair Value 7,692,236 5,226,926
Available-for-Sale, Unrealized Losses (704,831) (654,333)
U.S. Treasury    
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value 21,915 0
Available-for-Sale, Less than 12 months, Unrealized Losses (32) 0
Available-for-Sale, 12 months or longer, Fair Value 182,418 184,175
Available-for-Sale, 12 months or longer, Unrealized Losses (11,333) (7,615)
Available-for-Sale, Fair Value 204,333 184,175
Available-for-Sale, Unrealized Losses (11,365) (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 183,666 79,916
Available-for-Sale, Less than 12 months, Unrealized Losses (1,636) (78)
Available-for-Sale, 12 months or longer, Fair Value 1,143,200 1,173,044
Available-for-Sale, 12 months or longer, Unrealized Losses (137,377) (134,717)
Available-for-Sale, Fair Value 1,326,866 1,252,960
Available-for-Sale, Unrealized Losses (139,013) (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 2,948,237 252,875
Available-for-Sale, Less than 12 months, Unrealized Losses (29,525) (953)
Available-for-Sale, 12 months or longer, Fair Value 2,927,560 3,157,476
Available-for-Sale, 12 months or longer, Unrealized Losses (503,599) (486,252)
Available-for-Sale, Fair Value 5,875,797 3,410,351
Available-for-Sale, Unrealized Losses (533,124) (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 20,816 6,561
Available-for-Sale, Less than 12 months, Unrealized Losses (142) (17)
Available-for-Sale, 12 months or longer, Fair Value 146,548 234,389
Available-for-Sale, 12 months or longer, Unrealized Losses (15,401) (17,269)
Available-for-Sale, Fair Value 167,364 240,950
Available-for-Sale, Unrealized Losses (15,543) (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 12,876 11,734
Available-for-Sale, 12 months or longer, Unrealized Losses (951) (2,085)
Available-for-Sale, Fair Value 12,876 11,734
Available-for-Sale, Unrealized Losses (951) (2,085)
Other securities    
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]    
Available-for-Sale, Less than 12 months, Fair Value 12,679 1,766
Available-for-Sale, Less than 12 months, Unrealized Losses (24) (88)
Available-for-Sale, 12 months or longer, Fair Value 92,321 124,990
Available-for-Sale, 12 months or longer, Unrealized Losses (4,811) (5,259)
Available-for-Sale, Fair Value 105,000 126,756
Available-for-Sale, Unrealized Losses $ (4,835) $ (5,347)