v3.26.3
Fair Value of Assets and Liabilities - Schedule of Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Sep. 30, 2025
Financial Assets:      
Interest-bearing deposits with banks $ 3,557,687 $ 3,180,553 $ 3,422,452
Available-for-sale securities 7,569,498 6,236,263 5,274,124
Held-to-maturity securities 2,393,520 2,785,147 2,860,970
Equity securities with readily determinable fair value 64,811 63,770 63,445
FHLB and FRB stock, at cost 296,171 291,881 282,755
Mortgage loans held-for-sale, at fair value 307,748 340,745 333,883
Accrued interest receivable and other 1,946,561 1,617,682 1,614,674
Financial Liabilities:      
FHLB advances 3,450,680 3,451,309 3,151,309
Other borrowings 355,554 477,966 579,328
Subordinated notes 298,903 298,636 298,536
Junior subordinated debentures 253,566 253,566 253,566
Carrying Value      
Financial Assets:      
Cash and cash equivalents 635,657 467,938 565,469
Interest-bearing deposits with banks 3,557,687 3,180,553 3,422,452
Available-for-sale securities 7,569,498 6,236,263 5,274,124
Held-to-maturity securities 3,120,503 3,343,905 3,438,406
Equity securities with readily determinable fair value 64,811 63,770 63,445
FHLB and FRB stock, at cost 296,171 291,881 282,755
Mortgage loans held-for-sale, at fair value 307,748 340,745 333,883
Nonqualified deferred compensation assets 18,867 18,112 17,902
Derivative assets 205,591 179,667 208,957
Accrued interest receivable and other 593,339 552,197 587,274
Total 73,174,443 67,780,132 66,258,149
Financial Liabilities:      
Non-maturity deposits 51,190,169 47,839,241 46,292,925
Deposits with stated maturities 11,245,047 9,877,950 10,418,456
FHLB advances 3,450,680 3,451,309 3,151,309
Other borrowings 355,554 477,966 579,328
Subordinated notes 298,903 298,636 298,536
Junior subordinated debentures 253,566 253,566 253,566
Derivative liabilities 375,745 123,774 141,705
Accrued interest payable 62,219 62,884 69,453
Total financial liabilities 67,231,883 62,385,326 61,205,278
Carrying Value | Loans held-for-investment, at fair value      
Financial Assets:      
Loans held-for-investment 145,750 151,590 129,593
Carrying Value | Loans held-for-investment, at amortized cost      
Financial Assets:      
Loans held-for-investment 56,658,821 52,953,511 51,933,889
Fair Value      
Financial Assets:      
Cash and cash equivalents 635,657 467,938 565,469
Interest-bearing deposits with banks 3,557,687 3,180,553 3,422,452
Available-for-sale securities 7,569,498 6,236,263 5,274,124
Held-to-maturity securities 2,393,520 2,785,147 2,860,970
Equity securities with readily determinable fair value 64,811 63,770 63,445
FHLB and FRB stock, at cost 296,171 291,881 282,755
Mortgage loans held-for-sale, at fair value 307,748 340,745 333,883
Nonqualified deferred compensation assets 18,867 18,112 17,902
Derivative assets 205,591 179,667 208,957
Accrued interest receivable and other 593,339 552,197 587,274
Total 71,571,690 66,651,364 65,002,385
Financial Liabilities:      
Non-maturity deposits 51,190,169 47,839,241 46,292,925
Deposits with stated maturities 11,229,646 9,890,485 10,424,097
FHLB advances 3,443,200 3,472,538 3,185,090
Other borrowings 355,554 478,072 579,479
Subordinated notes 292,731 296,487 295,974
Junior subordinated debentures 253,515 253,591 253,591
Derivative liabilities 375,745 123,774 141,705
Accrued interest payable 62,219 62,884 69,453
Total financial liabilities 67,202,779 62,417,072 61,242,314
Fair Value | Loans held-for-investment, at fair value      
Financial Assets:      
Loans held-for-investment 145,750 151,590 129,593
Fair Value | Loans held-for-investment, at amortized cost      
Financial Assets:      
Loans held-for-investment $ 55,783,051 $ 52,383,501 $ 51,255,561