v3.25.2
Fair Value - Estimated fair value and related carrying amount, of the Company's financial instruments (Details) - USD ($)
$ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Financial assets:      
Trading securities $ 95,306   $ 102,932
Financial liabilities:      
Other derivative financial instruments (mortgage banking related) (275,258) $ 150,861  
Carrying Amount      
Financial assets:      
Cash and cash equivalents 3,464,106   1,392,067
Trading securities 95,306   102,932
Investment securities 8,431,345   6,798,876
Mortgage loans held for sale 318,985   279,426
Loans, net of allowance for credit losses 46,646,201   33,437,647
Accrued interest receivable 227,556   163,402
Mortgage servicing rights 85,836   89,795
SBA servicing asset 5,801   6,028
Interest rate swap - non-designated hedge 210,999   160,407
Other derivative financial instruments (mortgage banking related) $ 3,899   $ 1,083
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Derivative Asset, Noncurrent   Derivative Asset, Noncurrent
Financial liabilities:      
Noninterest-bearing $ 13,719,030   $ 10,192,117
Interest-bearing other than time deposits 32,269,471   23,703,027
Time deposits 7,708,460   4,165,722
Federal funds purchased and securities sold under agreements to repurchase 630,558   514,912
Corporate and subordinated debentures 1,099,705   391,534
Accrued interest payable 52,130   40,739
Interest rate swap - non-designated hedge 611,310   878,046
Other derivative financial instruments (mortgage banking related) 974   1,809
Fair Value      
Financial assets:      
Cash and cash equivalents 3,464,106   1,392,067
Trading securities 95,306   102,932
Investment securities 8,067,102   6,378,734
Mortgage loans held for sale 319,939   281,662
Loans, net of allowance for credit losses 46,339,114   32,448,618
Accrued interest receivable 227,556   163,402
Mortgage servicing rights 85,836   89,795
SBA servicing asset 5,801   6,028
Interest rate swap - non-designated hedge 210,999   160,407
Other derivative financial instruments (mortgage banking related) 3,899   1,083
Financial liabilities:      
Noninterest-bearing 13,719,030   10,192,117
Interest-bearing other than time deposits 32,269,471   23,703,027
Time deposits 7,683,701   4,145,687
Federal funds purchased and securities sold under agreements to repurchase 630,558   514,912
Corporate and subordinated debentures 1,104,781   377,616
Accrued interest payable 52,130   40,739
Interest rate swap - non-designated hedge 611,310   878,046
Other derivative financial instruments (mortgage banking related) 974   1,809
Quoted Prices In Active Markets for Identical Assets (Level 1)      
Financial assets:      
Cash and cash equivalents 3,464,106   1,392,067
Investment securities 274,869   187,266
Significant Other Observable Inputs (Level 2)      
Financial assets:      
Trading securities 95,306   102,932
Investment securities 7,709,615   6,155,120
Mortgage loans held for sale 319,939   281,662
Accrued interest receivable 34,054   25,035
Interest rate swap - non-designated hedge 210,999   160,407
Other derivative financial instruments (mortgage banking related) 3,899   1,083
Financial liabilities:      
Noninterest-bearing 13,719,030   10,192,117
Interest-bearing other than time deposits 32,269,471   23,703,027
Time deposits 7,683,701   4,145,687
Federal funds purchased and securities sold under agreements to repurchase 630,558   514,912
Corporate and subordinated debentures 1,104,781   377,616
Accrued interest payable 52,130   40,739
Interest rate swap - non-designated hedge 611,310   878,046
Other derivative financial instruments (mortgage banking related) 974   1,809
Significant Unobservable Inputs (Level 3)      
Financial assets:      
Investment securities 82,618   36,348
Loans, net of allowance for credit losses 46,339,114   32,448,618
Accrued interest receivable 193,502   138,367
Mortgage servicing rights 85,836   89,795
SBA servicing asset $ 5,801   $ 6,028