v3.26.1
Fair Value Measurement (Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis) (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale $ 11,131,000 $ 11,112,000
Loans held for sale 61,000 262,000
Loans Receivable, Fair Value Disclosure 70,000 78,000
Servicing Asset at Fair Value, Amount 105,000 99,000
Derivative Asset 85,000 84,000
Total assets measured at fair value 11,535,000 11,717,000
Junior subordinated debentures, at fair value 339,000 338,000
Derivative Liability 189,000 179,000
Total liabilities measured at fair value 528,000 517,000
Investments in mutual funds and other securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity and Other Investment Securities, Excluding Investments Measured At Net Asset Value Per Share 62,000 63,000
Equity securities held in rabbi trusts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity and Other Investment Securities, Excluding Investments Measured At Net Asset Value Per Share 21,000 19,000
U.S. Treasury and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 1,231,000 1,300,000
Obligations of states and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 1,594,000 1,629,000
Mortgage-backed securities and collateralized mortgage obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 8,306,000 8,183,000
Interest rate futures    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative Asset 1,000  
Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative Asset 84,000 84,000
Derivative Liability 189,000 179,000
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans held for sale 0 0
Loans Receivable, Fair Value Disclosure 0 0
Servicing Asset at Fair Value, Amount 0 0
Total assets measured at fair value 341,000 291,000
Junior subordinated debentures, at fair value 0 0
Total liabilities measured at fair value 0 0
Level 1 | Investments in mutual funds and other securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity and Other Investment Securities, Excluding Investments Measured At Net Asset Value Per Share 62,000 63,000
Level 1 | Equity securities held in rabbi trusts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity and Other Investment Securities, Excluding Investments Measured At Net Asset Value Per Share 21,000 19,000
Level 1 | U.S. Treasury and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 257,000 209,000
Level 1 | Obligations of states and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 0 0
Level 1 | Mortgage-backed securities and collateralized mortgage obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 0 0
Level 1 | Interest rate futures    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative Asset 1,000  
Level 1 | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative Asset 0 0
Derivative Liability 0 0
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans held for sale 61,000 262,000
Loans Receivable, Fair Value Disclosure 70,000 78,000
Servicing Asset at Fair Value, Amount 0 0
Total assets measured at fair value 11,089,000 11,327,000
Junior subordinated debentures, at fair value 0 0
Total liabilities measured at fair value 189,000 179,000
Level 2 | Investments in mutual funds and other securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity and Other Investment Securities, Excluding Investments Measured At Net Asset Value Per Share 0 0
Level 2 | Equity securities held in rabbi trusts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity and Other Investment Securities, Excluding Investments Measured At Net Asset Value Per Share 0 0
Level 2 | U.S. Treasury and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 974,000 1,091,000
Level 2 | Obligations of states and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 1,594,000 1,629,000
Level 2 | Mortgage-backed securities and collateralized mortgage obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 8,306,000 8,183,000
Level 2 | Interest rate futures    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative Asset 0  
Level 2 | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative Asset 84,000 84,000
Derivative Liability 189,000 179,000
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Loans held for sale 0 0
Loans Receivable, Fair Value Disclosure 0 0
Servicing Asset at Fair Value, Amount 105,000 99,000
Total assets measured at fair value 105,000 99,000
Junior subordinated debentures, at fair value 339,000 338,000
Total liabilities measured at fair value 339,000 338,000
Level 3 | Investments in mutual funds and other securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity and Other Investment Securities, Excluding Investments Measured At Net Asset Value Per Share 0 0
Level 3 | Equity securities held in rabbi trusts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity and Other Investment Securities, Excluding Investments Measured At Net Asset Value Per Share 0 0
Level 3 | U.S. Treasury and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 0 0
Level 3 | Obligations of states and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 0 0
Level 3 | Mortgage-backed securities and collateralized mortgage obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investment securities available for sale 0 0
Level 3 | Interest rate futures    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative Asset 0  
Level 3 | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative Asset 0 0
Derivative Liability $ 0 $ 0