v3.26.1
Financial Instruments - Estimated Fair Values of Financial Instruments (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Financial assets:    
Federal funds sold $ 5,450 $ 3,000
Investment securities - held-to-maturity 1,148,827 1,161,052
Carrying Amount    
Financial assets:    
Cash and cash equivalents 1,052,519 667,337
Federal funds sold 5,450 3,000
Investment securities - held-to-maturity 1,254,802 1,259,262
Loans receivable, net of impaired loans and allowance 16,593,768 15,186,203
Accrued interest receivable 108,384 108,939
FHLB, Federal Reserve & FNBB stock; other equity investments 232,353 225,288
Marketable equity securities 51,490 53,921
Financial liabilities:    
Demand and non-interest bearing 4,447,710 3,868,405
Savings and interest-bearing transaction accounts 12,423,361 11,792,828
Time deposits 2,242,034 1,818,724
Securities sold under agreements to repurchase 158,744 155,803
FHLB and other borrowed funds 450,250 500,250
Accrued interest payable 15,244 14,868
Subordinated debentures 279,602 279,265
Fair Value Measurements    
Financial assets:    
Cash and cash equivalents 1,052,519 667,337
Federal funds sold 5,450 3,000
Investment securities - held-to-maturity 1,148,827 1,161,052
Loans receivable, net of impaired loans and allowance 16,515,955 15,205,769
Accrued interest receivable 108,384 108,939
FHLB, Federal Reserve & FNBB stock; other equity investments 232,353 225,288
Marketable equity securities 51,490 53,921
Financial liabilities:    
Demand and non-interest bearing 4,447,710 3,868,405
Savings and interest-bearing transaction accounts 12,423,361 11,792,828
Time deposits 2,221,178 1,807,002
Securities sold under agreements to repurchase 158,744 155,803
FHLB and other borrowed funds 417,768 474,663
Accrued interest payable 15,244 14,868
Subordinated debentures 270,177 265,170
Level 1 | Fair Value Measurements    
Financial assets:    
Cash and cash equivalents 1,052,519 667,337
Federal funds sold 5,450 3,000
Investment securities - held-to-maturity 27,217 27,457
Loans receivable, net of impaired loans and allowance 0 0
Accrued interest receivable 108,384 108,939
FHLB, Federal Reserve & FNBB stock; other equity investments 0 0
Marketable equity securities 51,490 53,921
Financial liabilities:    
Demand and non-interest bearing 4,447,710 3,868,405
Savings and interest-bearing transaction accounts 12,423,361 11,792,828
Time deposits 0 0
Securities sold under agreements to repurchase 158,744 155,803
FHLB and other borrowed funds 0 0
Accrued interest payable 15,244 14,868
Subordinated debentures 0 0
Level 2 | Fair Value Measurements    
Financial assets:    
Cash and cash equivalents 0 0
Federal funds sold 0 0
Investment securities - held-to-maturity 1,121,610 1,133,595
Loans receivable, net of impaired loans and allowance 0 0
Accrued interest receivable 0 0
FHLB, Federal Reserve & FNBB stock; other equity investments 0 0
Marketable equity securities 0 0
Financial liabilities:    
Demand and non-interest bearing 0 0
Savings and interest-bearing transaction accounts 0 0
Time deposits 0 0
Securities sold under agreements to repurchase 0 0
FHLB and other borrowed funds 417,768 474,663
Accrued interest payable 0 0
Subordinated debentures 0 0
Level 3 | Fair Value Measurements    
Financial assets:    
Cash and cash equivalents 0 0
Federal funds sold 0 0
Investment securities - held-to-maturity 0 0
Loans receivable, net of impaired loans and allowance 16,515,955 15,205,769
Accrued interest receivable 0 0
FHLB, Federal Reserve & FNBB stock; other equity investments 232,353 225,288
Marketable equity securities 0 0
Financial liabilities:    
Demand and non-interest bearing 0 0
Savings and interest-bearing transaction accounts 0 0
Time deposits 2,221,178 1,807,002
Securities sold under agreements to repurchase 0 0
FHLB and other borrowed funds 0 0
Accrued interest payable 0 0
Subordinated debentures $ 270,177 $ 265,170