v3.26.3
Investment Securities - Securities with gross unrealized losses (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Securities Held to Maturity, Gross Unrealized Losses    
Twelve Months or More $ 386,023 $ 315,180
Securities Held to Maturity, Fair Value    
Twelve Months or More 1,519,276 1,732,850
Securities Available for Sale, Gross Unrealized Losses    
Less Than Twelve Months 145,047 1,985
Twelve Months or More 573,813 420,004
Securities Available for Sale, Fair Value    
Less Than Twelve Months 3,821,485 665,711
Twelve Months or More 2,363,898 2,633,067
U.S. Government agencies    
Securities Held to Maturity, Gross Unrealized Losses    
Twelve Months or More 21,449 15,767
Securities Held to Maturity, Fair Value    
Twelve Months or More 111,441 117,146
Residential mortgage-backed securities issued by U.S. government agencies or sponsored enterprises    
Securities Held to Maturity, Gross Unrealized Losses    
Twelve Months or More 219,481 177,101
Securities Held to Maturity, Fair Value    
Twelve Months or More 835,270 975,923
Securities Available for Sale, Gross Unrealized Losses    
Less Than Twelve Months 48,240 459
Twelve Months or More 179,226 137,848
Securities Available for Sale, Fair Value    
Less Than Twelve Months 1,149,122 145,357
Twelve Months or More 685,215 803,407
Residential collateralized mortgage-obligations issued by U.S. government agencies or sponsored enterprises    
Securities Held to Maturity, Gross Unrealized Losses    
Twelve Months or More 69,930 55,232
Securities Held to Maturity, Fair Value    
Twelve Months or More 285,786 323,874
Securities Available for Sale, Gross Unrealized Losses    
Less Than Twelve Months 48,097 46
Twelve Months or More 57,720 47,059
Securities Available for Sale, Fair Value    
Less Than Twelve Months 1,720,299 40,399
Twelve Months or More 238,313 278,620
Commercial mortgage-backed securities issued by U.S. government agencies or sponsored enterprises    
Securities Held to Maturity, Gross Unrealized Losses    
Twelve Months or More 65,771 58,332
Securities Held to Maturity, Fair Value    
Twelve Months or More 253,009 278,579
Securities Available for Sale, Gross Unrealized Losses    
Less Than Twelve Months 24,057 228
Twelve Months or More 89,707 73,814
Securities Available for Sale, Fair Value    
Less Than Twelve Months 584,234 152,299
Twelve Months or More 379,753 423,165
State and municipal obligations    
Securities Available for Sale, Gross Unrealized Losses    
Less Than Twelve Months 21,868 572
Twelve Months or More 218,894 134,645
Securities Available for Sale, Fair Value    
Less Than Twelve Months 264,070 43,620
Twelve Months or More 765,244 903,784
Small Business Administration loan-backed securities    
Securities Held to Maturity, Gross Unrealized Losses    
Twelve Months or More 9,392 8,748
Securities Held to Maturity, Fair Value    
Twelve Months or More 33,770 37,328
Securities Available for Sale, Gross Unrealized Losses    
Less Than Twelve Months 2,684 680
Twelve Months or More 27,371 25,408
Securities Available for Sale, Fair Value    
Less Than Twelve Months 93,861 284,036
Twelve Months or More 283,268 202,322
Corporate securities    
Securities Available for Sale, Gross Unrealized Losses    
Less Than Twelve Months 101  
Twelve Months or More 895 1,230
Securities Available for Sale, Fair Value    
Less Than Twelve Months 9,899  
Twelve Months or More $ 12,105 $ 21,769