v3.26.1
Loans, Leases and Allowance for Credit Losses - Additional Information (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
Financing Receivable, Allowance for Credit Loss [Line Items]        
Unamortized loan fees $ 124.0   $ 120.0  
Financing receivable, unamortized premium 193.0   186.0  
Loans Past Due 90 Days or More and Still Accruing 344.0   356.0  
Interest income associated with loans on nonaccrual status 9.2 $ 8.0    
Modified loans current with contractual payments 131.0   114.0  
Modified loans on nonaccrual status 55.0   89.0  
Amortized cost basis 34.0 299.0    
Interest receivable 284.0   287.0  
Loan purchases 935.0 335.0    
Loan sales 107.0 218.0    
Charge-off 6.1      
Loss on sale of loan   (2.6)    
Total 461.1 388.6 460.6 $ 373.8
Residential EBO        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Loans Past Due 90 Days or More and Still Accruing 288.0   290.0  
Amortized cost basis 86.0 147.0    
Interest receivable, allowance 1.2   1.2  
Loan purchases 0.0 127.0    
Total 0.0 0.0 0.0 0.0
Residential EBO | Financial Asset, Current to 89 Days Past Due        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Modified loans 48.0   27.0  
Residential EBO | Over 90 days Past Due        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Modified loans 106.0   123.0  
Residential        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Loans Past Due 90 Days or More and Still Accruing 53.0   51.0  
Recorded investment for which formal foreclosure proceedings are in process 105.0   107.0  
Total 23.7 19.7 23.7 19.7
CRE - owner occupied        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Loans Past Due 90 Days or More and Still Accruing 0.0   0.0  
Total 3.6 $ 3.7 $ 3.4 $ 3.4
CRE - owner occupied | Real Estate Collateral        
Financing Receivable, Allowance for Credit Loss [Line Items]        
Credit quality deterioration, purchase 13.0      
Credit quality deterioration, principal balance 13.0      
Total $ 0.0