v3.26.3
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES - Schedule of Changes in Allowance for Credit Losses (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period     $ 439.0    
Charge- Offs     (56.1)   $ (84.7)
Provision for Credit Losses $ 19.0 $ 24.0 59.5 $ 67.1  
Balance at End of Period 456.0   456.0   439.0
Unfunded loan commitment          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 19.1 21.0 20.1 21.4 21.4
Charge- Offs 0.0 0.0 0.0 0.0  
Recoveries 0.0 0.0 0.0 0.0  
Net (Charge- Offs) Recoveries 0.0 0.0 0.0 0.0  
Provision for Credit Losses 0.4 (0.9) (0.6) (1.3)  
Balance at End of Period 19.5 20.1 19.5 20.1 20.1
Total commercial loans and leases          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 311.4 294.0 305.4 279.7 279.7
Charge- Offs (10.6) (19.8) (48.3) (55.2)  
Recoveries 1.3 1.6 10.0 7.7  
Net (Charge- Offs) Recoveries (9.3) (18.2) (38.3) (47.5)  
Provision for Credit Losses 7.0 25.2 42.0 68.8  
Balance at End of Period 309.1 301.0 309.1 301.0 305.4
Total commercial loans and leases | Commercial real estate          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 166.9 179.5 175.9 166.9 166.9
Charge- Offs (4.9) (9.2) (18.4) (19.8) (30.0)
Recoveries 0.4 0.4 1.1 1.0  
Net (Charge- Offs) Recoveries (4.5) (8.8) (17.3) (18.8)  
Provision for Credit Losses 1.0 7.4 4.8 30.0  
Balance at End of Period 163.4 178.1 163.4 178.1 175.9
Total commercial loans and leases | Commercial and industrial          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 117.1 88.3 98.9 85.6 85.6
Charge- Offs (4.0) (9.2) (23.9) (31.6) (37.9)
Recoveries 0.5 1.0 7.3 6.0  
Net (Charge- Offs) Recoveries (3.5) (8.2) (16.6) (25.6)  
Provision for Credit Losses 6.0 14.9 37.3 35.0  
Balance at End of Period 119.6 95.0 119.6 95.0 98.9
Total commercial loans and leases | Commercial leases          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 22.7 21.6 26.2 22.9 22.9
Charge- Offs (0.3) 0.0 (2.3) (0.2) (0.2)
Recoveries 0.1 0.0 0.1 0.0  
Net (Charge- Offs) Recoveries (0.2) 0.0 (2.2) (0.2)  
Provision for Credit Losses (1.2) 1.7 (2.7) 0.6  
Balance at End of Period 21.3 23.3 21.3 23.3 26.2
Total commercial loans and leases | Other          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 4.7 4.6 4.4 4.3 4.3
Charge- Offs (1.4) (1.4) (3.7) (3.6) (4.7)
Recoveries 0.3 0.2 1.5 0.7  
Net (Charge- Offs) Recoveries (1.1) (1.2) (2.2) (2.9)  
Provision for Credit Losses 1.2 1.2 2.6 3.2  
Balance at End of Period 4.8 4.6 4.8 4.6 4.4
Total commercial loans and leases | Unfunded loan commitment          
Allowance for Loan and Lease Losses [Roll Forward]          
Provision for Credit Losses 0.4 (0.8) (0.5) (1.1)  
Total consumer loans          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 135.9 138.1 134.1 143.1 143.1
Charge- Offs (2.6) (2.4) (7.8) (9.3)  
Recoveries 0.9 0.9 2.2 2.8  
Net (Charge- Offs) Recoveries (1.7) (1.5) (5.6) (6.5)  
Provision for Credit Losses 12.2 (0.3) 17.9 (0.3)  
Balance at End of Period 146.4 136.3 146.4 136.3 134.1
Total consumer loans | Direct installment          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 25.2 26.6 25.7 29.1 29.1
Charge- Offs (0.3) (0.1) (0.7) (0.7) (0.9)
Recoveries 0.2 0.1 0.4 0.4  
Net (Charge- Offs) Recoveries (0.1) 0.0 (0.3) (0.3)  
Provision for Credit Losses 0.1 (0.6) (0.2) (2.8)  
Balance at End of Period 25.2 26.0 25.2 26.0 25.7
Total consumer loans | Residential mortgages          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 94.0 95.4 92.4 95.9 95.9
Charge- Offs (0.5) (0.5) (2.0) (2.3) (2.4)
Recoveries 0.1 0.1 0.0 0.3  
Net (Charge- Offs) Recoveries (0.4) (0.4) (2.0) (2.0)  
Provision for Credit Losses 9.6 (0.8) 12.8 0.3  
Balance at End of Period 103.2 94.2 103.2 94.2 92.4
Total consumer loans | Indirect installment          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 9.6 9.3 9.0 9.5 9.5
Charge- Offs (1.6) (1.6) (4.5) (5.5) (7.6)
Recoveries 0.5 0.6 1.4 1.8  
Net (Charge- Offs) Recoveries (1.1) (1.0) (3.1) (3.7)  
Provision for Credit Losses 2.3 0.8 4.9 3.3  
Balance at End of Period 10.8 9.1 10.8 9.1 9.0
Total consumer loans | Consumer lines of credit          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 7.1 6.8 7.0 8.6 8.6
Charge- Offs (0.2) (0.2) (0.6) (0.8) (1.0)
Recoveries 0.1 0.1 0.4 0.3  
Net (Charge- Offs) Recoveries (0.1) (0.1) (0.2) (0.5)  
Provision for Credit Losses 0.2 0.3 0.4 (1.1)  
Balance at End of Period 7.2 7.0 7.2 7.0 7.0
Total consumer loans | Unfunded loan commitment          
Allowance for Loan and Lease Losses [Roll Forward]          
Provision for Credit Losses 0.0 (0.1) (0.1) (0.2)  
Allowance for credit losses on loans and leases          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 447.3 432.1 439.5 422.8 422.8
Charge- Offs (13.2) (22.2) (56.1) (64.5)  
Recoveries 2.2 2.5 12.2 10.5  
Net (Charge- Offs) Recoveries (11.0) (19.7) (43.9) (54.0)  
Provision for Credit Losses 19.2 24.9 59.9 68.5  
Balance at End of Period 455.5 437.3 455.5 437.3 439.5
Allowance for credit losses on loans and leases and allowance for unfunded loan commitments          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 466.4 453.1 459.6 444.2 444.2
Charge- Offs (13.2) (22.2) (56.1) (64.5)  
Recoveries 2.2 2.5 12.2 10.5  
Net (Charge- Offs) Recoveries (11.0) (19.7) (43.9) (54.0)  
Provision for Credit Losses 19.6 24.0 59.3 67.2  
Balance at End of Period $ 475.0 $ 457.4 $ 475.0 $ 457.4 $ 459.6