v3.26.1
Securities - Narrative (Details)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
USD ($)
debt_security
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
debt_security
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
debt_security
Schedule of Investments [Line Items]          
Transferred Securities, Unrealized Loss, Before Tax $ 92,000,000.0   $ 92,000,000.0   $ 96,600,000
Securities transferred, Unrealized Loss, Net of Tax 72,700,000   72,700,000   76,300,000
Fair value of securities transferred from AFS to HTM     0   0
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]          
Net gain (loss) on sale of securities AFS 0 $ 0 0 $ 554,000  
Net realized losses on AFS securities       1,200,000  
Gross realized gains on AFS securities       600,000  
Proceeds from sale of AFS securities     0 120,242,000  
Equity investments 9,531,000   9,531,000   9,574,000
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]          
Sale of HTM portfolio 0 0 0 0  
Interest receivable 43,392,000   43,392,000   $ 41,809,000
FHLB stock with other-than-temporary impairment $ 0   $ 0    
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | debt_security 195   195   161
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Credit Loss Expense (Reversal) $ 0 (9,000)   55,000  
Less: Net gains recognized during the period on equity investments sold during the period 0 $ 0 $ 0 $ 0  
Debt Securities, Available-for-Sale, Accrued Interest 9,900,000   9,900,000   $ 9,400,000
Debt Securities, Held-to-Maturity, Accrued Interest 12,500,000   12,500,000   12,700,000
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Nonaccrual 0   0   0
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss 1,211,925,000   1,211,925,000   1,247,502,000
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0   0   0
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest $ 25,000   $ 25,000   25,000
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] Interest receivable   Interest receivable    
State and political subdivisions          
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]          
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss $ 1,044,132,000   $ 1,044,132,000   1,042,986,000
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0   0   0
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest 24,000   24,000   25,000
Corporate bonds and other          
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]          
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss 86,280,000   86,280,000   98,609,000
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0   0   0
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest 1,000   1,000   0
Asset Pledged as Collateral          
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]          
Debt Securities 2,210,000,000   2,210,000,000   1,940,000,000
Asset Pledged As Collateral, Excess Amount          
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]          
Debt Securities 279,300,000   279,300,000   241,800,000
Financial Asset, Past Due          
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]          
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, before Allowance for Credit Loss $ 0   $ 0   $ 0