v3.26.1
Derivative Financial Instruments Derivative Financial Instruments - Narrative (Details)
 3 Months Ended
Mar. 31, 2026
USD ($)
instrument
Dec. 31, 2025
USD ($)
instrument
Derivative [Line Items]    
Cash collateral pledged for derivatives $ 82,700,000 $ 29,500,000
CashCollateralPostedForDerivativesInLiabilityPosition 24,300,000 $ 7,600,000
Interest expense, long-term debt 60,000  
Derivative, amount of hedged item 392,100,000  
Fair value hedges, cumulative basis adjustments 5,500,000  
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 25 23
Non-hedging derivatives, notional amoount $ 457,700,000 $ 338,100,000
Maximum exposure $ 1,400,000 $ 510,000
Risk participation agreement - lead bank    
Derivative [Line Items]    
Instruments held | instrument 54 47
Non-hedging derivatives, notional amoount $ 684,800,000 $ 603,100,000
Interest rate contract    
Derivative [Line Items]    
Unrealized losses, net of tax to AOCI 12,100,000  
Amount reclassified from AOCI into interest income on loans 1,000,000.0  
Amount reclassified from AOCI as a decrease to interest income $ 4,000,000.0  
Maximum period to hedge forecasted transactions 2 years 2 months 1 day  
Loans Receivable | Not Designated as Hedging Instrument    
Derivative [Line Items]    
Credit risk exposure, net of collateral pledged, relating to derivatives $ 43,900,000 $ 40,900,000