v3.26.1
Allowance for Credit Losses - Loan Modifications to Borrowers Experiencing Financial Difficulty (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     $ 3,632,000 $ 17,935,000  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted   $ 549,000      
Commitments related to borrowers experiencing financial difficulty $ 0   0   $ 0
Aggregate commitments to extend credit, standby letters of credit and commercial letters of credit 6,800,000,000   6,800,000,000   $ 6,900,000,000
30 - 59 Days Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     208,000 707,000  
60 - 89 Days Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     47,000 1,237,000  
90 Days or Greater Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     42,000 96,000  
Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     297,000 2,040,000  
Not Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     3,335,000 15,895,000  
Commercial and Industrial          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     500,000 9,775,000  
Commercial and Industrial | 30 - 59 Days Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     86,000    
Commercial and Industrial | 90 Days or Greater Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       16,000  
Commercial and Industrial | Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     86,000 16,000  
Commercial and Industrial | Not Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     414,000 9,759,000  
Construction          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       904,000  
Construction | 60 - 89 Days Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       904,000  
Construction | Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       904,000  
Commercial Real Estate          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       2,143,000  
Commercial Real Estate | Not Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       2,143,000  
Residential mortgage          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     1,600,000 2,906,000  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted   549,000      
Residential mortgage | 30 - 59 Days Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       549,000  
Residential mortgage | 60 - 89 Days Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       299,000  
Residential mortgage | Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       848,000  
Residential mortgage | Not Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     1,600,000 2,058,000  
Consumer          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     1,532,000 2,207,000  
Consumer | 30 - 59 Days Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     122,000 158,000  
Consumer | 60 - 89 Days Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     47,000 34,000  
Consumer | 90 Days or Greater Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     42,000 80,000  
Consumer | Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     211,000 272,000  
Consumer | Not Past Due          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis     1,321,000 1,935,000  
Interest Rate Reduction          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis 414,000 544,000 771,000 1,052,000  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted 238,000 410,000 347,000 501,000  
Interest Rate Reduction | Consumer          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis $ 414,000 $ 544,000 $ 771,000 $ 1,052,000  
% of Total Class of Financing Receivable 0.04% 0.05% 0.07% 0.10%  
Reduced weighted-average contractual interest rate 13.52% 12.98% 13.57% 13.04%  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted $ 238,000 $ 410,000 $ 347,000 $ 501,000  
Term Extension          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis 145,000 $ 3,789,000 632,000 $ 12,955,000  
% of Total Class of Financing Receivable   0.03%   0.09%  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted 570,000 $ 1,264,000 847,000 $ 1,660,000  
Term Extension | Commercial and Industrial          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis $ 74,000 $ 731,000 $ 238,000 $ 9,620,000  
% of Total Class of Financing Receivable   0.03% 0.01% 0.41%  
Added weighted-average years to the life of loans 4 years 10 months 24 days 2 years 4 years 10 months 24 days 7 months 6 days  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted $ 570,000 $ 57,000 $ 594,000 $ 128,000  
Term Extension | Construction          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis   $ 904,000   $ 904,000  
% of Total Class of Financing Receivable   0.10%   0.10%  
Added weighted-average years to the life of loans   2 months 12 days   2 months 12 days  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted   $ 904,000   $ 904,000  
Term Extension | Commercial Real Estate          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis   $ 940,000   $ 1,138,000  
% of Total Class of Financing Receivable   0.02%   0.03%  
Added weighted-average years to the life of loans   2 months 12 days   3 months 18 days  
Term Extension | Residential mortgage          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis   $ 714,000 $ 253,000 $ 714,000  
% of Total Class of Financing Receivable   0.02%   0.02%  
Added weighted-average years to the life of loans   3 months 18 days 2 years 3 months 18 days  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted   $ 299,000 $ 253,000 $ 608,000  
Term Extension | Consumer          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis $ 71,000 $ 500,000 $ 141,000 $ 579,000  
% of Total Class of Financing Receivable   0.05% 0.01% 0.06%  
Added weighted-average years to the life of loans 4 years 9 months 18 days 1 month 6 days 4 years 10 months 24 days 8 months 12 days  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted   $ 4,000   $ 20,000  
Other-Than-Insignificant Payment Delay          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis $ 0 1,184,000 $ 0 $ 2,189,000  
% of Total Class of Financing Receivable       0.02%  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted       $ 549,000  
Other-Than-Insignificant Payment Delay | Commercial Real Estate          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis       $ 1,005,000  
% of Total Class of Financing Receivable       0.02%  
Deferred loan payments       $ 209,000  
Other-Than-Insignificant Payment Delay | Residential mortgage          
Loan Modifications to Borrowers Experiencing Financial Difficulty          
Amortized Cost Basis   $ 1,184,000   $ 1,184,000  
% of Total Class of Financing Receivable   0.03%   0.03%  
Amortized Cost Basis of Modified Loans That Subsequently Defaulted       $ 549,000  
Deferred loan payments   $ 65,000   $ 65,000