v3.26.1
Derivative Financial Instruments Derivative Financial Instruments - Narrative (Details)
 6 Months Ended
Jun. 30, 2026
USD ($)
instrument
Dec. 31, 2025
USD ($)
instrument
Derivative [Line Items]    
Cash collateral pledged for derivatives $ 116,200,000 $ 29,500,000
CashCollateralPostedForDerivativesInLiabilityPosition 33,700,000 $ 7,600,000
Interest expense, long-term debt 413,000  
Derivative, amount of hedged item 387,500,000  
Fair value hedges, cumulative basis adjustments 10,200,000  
Senior Notes | 5.301% Senior Notes, Due February 2032    
Derivative [Line Items]    
Senior unsecured credit-linked notes $ 400,000,000.0  
Risk participation agreement - participant bank    
Derivative [Line Items]    
Instruments held | instrument 24 23
Non-hedging derivatives, notional amoount $ 425,600,000 $ 338,100,000
Maximum exposure $ 3,400,000 $ 510,000
Risk participation agreement - lead bank    
Derivative [Line Items]    
Instruments held | instrument 52 47
Non-hedging derivatives, notional amoount $ 665,100,000 $ 603,100,000
Interest rate contract    
Derivative [Line Items]    
Unrealized losses, net of tax to AOCI 24,700,000  
Amount reclassified from AOCI into interest income on loans 2,200,000  
Amount reclassified from AOCI as a decrease to interest income $ (10,400,000)  
Maximum period to hedge forecasted transactions 2 years 1 month 2 days  
Loans Receivable | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Credit risk exposure, net of collateral pledged, relating to derivatives $ 15,300,000 $ 40,900,000