v3.26.1
Derivative Financial Instruments (Details) - USD ($)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Dec. 31, 2026
Derivative Financial Instruments            
Notional Amount $ 34,685,762,000   $ 34,685,762,000   $ 32,426,542,000  
Estimated Fair Value Gain 148,889,000   148,889,000   222,886,000  
Estimated Fair Value Loss 606,665,000   606,665,000   554,748,000  
Fair value of the interest rate swap derivatives, other assets 147,300,000   147,300,000   221,700,000  
Fair value of the interest rate swap derivatives, other liabilities 606,400,000   606,400,000   554,400,000  
Reduction in derivative asset fair value     461,400,000   333,700,000  
Estimated gain (loss) on fair value     338,000   69,000  
Mortgage loan pipeline            
Obligation under forward commitments, the fair value of those obligations along with the fair value of derivative instruments associated with forward commitments            
Obligation 92,055,000   92,055,000   55,318,000  
Expected closures            
Obligation under forward commitments, the fair value of those obligations along with the fair value of derivative instruments associated with forward commitments            
Obligation 80,637,000   80,637,000   48,106,000  
Cash flow hedge | Borrower            
Derivative Financial Instruments            
Collateral provided 325,800,000   325,800,000      
Cash flow hedge | Counterparty            
Derivative Financial Instruments            
Collateral provided 78,400,000   78,400,000      
Cash flow hedge | Interest-bearing deposits | Counterparty            
Derivative Financial Instruments            
Cash collateral 29,600,000   29,600,000      
Interest rate contracts            
Derivative Financial Instruments            
Notional Amount 31,500,000,000   31,500,000,000   29,600,000,000  
Mortgage servicing rights hedging | Non-designated hedges            
Derivative Financial Instruments            
Notional Amount 264,000,000   264,000,000   192,000,000  
Estimated Fair Value Gain 338,000   338,000   69,000  
Mortgage loan pipeline commitments hedging            
Obligation under forward commitments, the fair value of those obligations along with the fair value of derivative instruments associated with forward commitments            
Obligation 1,209,000   1,209,000   982,000  
Mortgage loan pipeline commitments hedging | Non-designated hedges            
Derivative Financial Instruments            
Notional Amount 108,500,000   108,500,000   81,000,000  
Estimated Fair Value Gain 1,209,000   1,209,000   982,000  
Estimated Fair Value Loss 261,000   261,000   315,000  
Forward commitments            
Derivative Financial Instruments            
Estimated Fair Value Loss (261,000)   (261,000)   (315,000)  
Obligation under forward commitments, the fair value of those obligations along with the fair value of derivative instruments associated with forward commitments            
Obligation 108,500,000   108,500,000   81,000,000  
Interest rate swap            
Derivative Financial Instruments            
Net gain (loss) 86,000 $ (59,000) 1,200,000 $ (231,000)    
Interest rate swap | Fair Value Hedging | Counterparty            
Derivative Financial Instruments            
Notional Amount 2,615,000   2,615,000   2,615,000 $ 2,600,000
Estimated Fair Value Gain 62,000   62,000   44,000  
Amortized cost basis of loans hedged 2,600,000   2,600,000   2,600,000  
Interest rate swap | Non-designated hedges | Borrower            
Derivative Financial Instruments            
Notional Amount 15,923,186,000   15,923,186,000   14,912,622,000  
Estimated Fair Value Gain 58,347,000   58,347,000   143,879,000  
Estimated Fair Value Loss 606,404,000   606,404,000   554,433,000  
Interest rate swap | Non-designated hedges | Counterparty            
Derivative Financial Instruments            
Notional Amount 15,575,461,000   15,575,461,000   14,719,305,000  
Estimated Fair Value Gain 88,952,000   88,952,000   77,799,000  
Total gross derivative instruments, before netting, Notional amount 1,693,908,000   1,693,908,000   1,844,842,000  
Total gross derivative instruments, before netting, Estimated fair value gain     86,424,000   81,240,000  
Total gross derivative instruments, before netting, Estimated fair value loss     1,232,000   3,781,000  
Less: Netting adjustment, Notional amount 126,791,000   126,791,000   221,941,000  
Less: Netting adjustment, Estimated fair value gain     (1,232,000)   (3,781,000)  
Less: Netting adjustment, Estimated fair value loss     (1,232,000)   (3,781,000)  
Total gross derivative instruments, after netting, Notional amount 1,693,908,000   1,693,908,000   1,844,842,000  
Total gross derivative instruments, after netting, Estimated fair value gain     85,192,000   77,459,000  
Total gross derivative instruments, after netting, Estimated fair value loss     0   0  
Master netting arrangement collateral obligation to return cash offset against derivative asset 29,600,000   29,600,000   25,900,000  
Securities pledged 26,500,000   26,500,000   28,100,000  
Master netting arrangement collateral obligation cash paid offset against derivative asset 2,400,000   2,400,000   1,700,000  
Reduction in derivative asset fair value     461,400,000   333,700,000  
Interest rate swap | Economic hedges | Counterparty            
Derivative Financial Instruments            
Notional Amount 2,812,000,000   2,812,000,000   2,519,000,000  
Estimated Fair Value Gain $ (19,000)   $ (19,000)   $ 113,000