v3.26.1
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES - Schedule of Changes in Allowance for Credit Losses (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period     $ 439.0    
Charge- Offs     (43.0)   $ (84.7)
Provision for Credit Losses $ 22.0 $ 26.0 39.8 $ 43.1  
Balance at End of Period 447.0   447.0   439.0
Unfunded loan commitment          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 19.2 20.3 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 (0.1) 0.7 (1.0) (0.4)  
Balance at End of Period 19.1 21.0 19.1 21.0 20.1
Total commercial loans and leases          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 306.2 289.2 305.4 279.7 279.7
Charge- Offs (17.1) (22.3) (37.7) (35.4)  
Recoveries 2.3 2.9 8.7 6.1  
Net (Charge- Offs) Recoveries (14.8) (19.4) (29.0) (29.3)  
Provision for Credit Losses 20.0 24.2 35.0 43.6  
Balance at End of Period 311.4 294.0 311.4 294.0 305.4
Total commercial loans and leases | Commercial real estate          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 165.7 173.4 175.9 166.9 166.9
Charge- Offs (5.2) (3.0) (13.5) (10.6) (30.0)
Recoveries 0.5 0.2 0.7 0.6  
Net (Charge- Offs) Recoveries (4.7) (2.8) (12.8) (10.0)  
Provision for Credit Losses 5.9 8.9 3.8 22.6  
Balance at End of Period 166.9 179.5 166.9 179.5 175.9
Total commercial loans and leases | Commercial and industrial          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 109.7 88.6 98.9 85.6 85.6
Charge- Offs (10.7) (18.1) (19.9) (22.4) (37.9)
Recoveries 0.9 2.5 6.8 5.0  
Net (Charge- Offs) Recoveries (9.8) (15.6) (13.1) (17.4)  
Provision for Credit Losses 17.2 15.3 31.3 20.1  
Balance at End of Period 117.1 88.3 117.1 88.3 98.9
Total commercial loans and leases | Commercial leases          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 26.3 22.8 26.2 22.9 22.9
Charge- Offs 0.0 (0.1) (2.0) (0.2) (0.2)
Recoveries 0.0 0.0 0.0 0.0  
Net (Charge- Offs) Recoveries 0.0 (0.1) (2.0) (0.2)  
Provision for Credit Losses (3.6) (1.1) (1.5) (1.1)  
Balance at End of Period 22.7 21.6 22.7 21.6 26.2
Total commercial loans and leases | Other          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 4.5 4.4 4.4 4.3 4.3
Charge- Offs (1.2) (1.1) (2.3) (2.2) (4.7)
Recoveries 0.9 0.2 1.2 0.5  
Net (Charge- Offs) Recoveries (0.3) (0.9) (1.1) (1.7)  
Provision for Credit Losses 0.5 1.1 1.4 2.0  
Balance at End of Period 4.7 4.6 4.7 4.6 4.4
Total commercial loans and leases | Unfunded loan commitment          
Allowance for Loan and Lease Losses [Roll Forward]          
Provision for Credit Losses 0.0 0.8 (0.9) (0.3)  
Total consumer loans          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 136.8 139.7 134.1 143.1 143.1
Charge- Offs (3.0) (3.6) (5.3) (6.9)  
Recoveries 0.8 1.2 1.4 1.9  
Net (Charge- Offs) Recoveries (2.2) (2.4) (3.9) (5.0)  
Provision for Credit Losses 1.3 0.8 5.7 0.0  
Balance at End of Period 135.9 138.1 135.9 138.1 134.1
Total consumer loans | Direct installment          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 25.8 28.1 25.7 29.1 29.1
Charge- Offs (0.2) (0.2) (0.4) (0.6) (0.9)
Recoveries 0.1 0.2 0.2 0.3  
Net (Charge- Offs) Recoveries (0.1) 0.0 (0.2) (0.3)  
Provision for Credit Losses (0.5) (1.5) (0.3) (2.2)  
Balance at End of Period 25.2 26.6 25.2 26.6 25.7
Total consumer loans | Residential mortgages          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 95.0 94.1 92.4 95.9 95.9
Charge- Offs (1.2) (1.4) (1.6) (1.8) (2.4)
Recoveries 0.0 0.1 0.0 0.2  
Net (Charge- Offs) Recoveries (1.2) (1.3) (1.6) (1.6)  
Provision for Credit Losses 0.2 2.6 3.2 1.1  
Balance at End of Period 94.0 95.4 94.0 95.4 92.4
Total consumer loans | Indirect installment          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 9.0 9.2 9.0 9.5 9.5
Charge- Offs (1.4) (1.7) (2.9) (3.9) (7.6)
Recoveries 0.5 0.8 0.9 1.2  
Net (Charge- Offs) Recoveries (0.9) (0.9) (2.0) (2.7)  
Provision for Credit Losses 1.5 1.0 2.6 2.5  
Balance at End of Period 9.6 9.3 9.6 9.3 9.0
Total consumer loans | Consumer lines of credit          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 7.0 8.3 7.0 8.6 8.6
Charge- Offs (0.2) (0.3) (0.4) (0.6) (1.0)
Recoveries 0.2 0.1 0.3 0.2  
Net (Charge- Offs) Recoveries 0.0 (0.2) (0.1) (0.4)  
Provision for Credit Losses 0.1 (1.3) 0.2 (1.4)  
Balance at End of Period 7.1 6.8 7.1 6.8 7.0
Total consumer loans | Unfunded loan commitment          
Allowance for Loan and Lease Losses [Roll Forward]          
Provision for Credit Losses (0.1) (0.1) (0.1) (0.1)  
Allowance for credit losses on loans and leases          
Allowance for Loan and Lease Losses [Roll Forward]          
Balance at Beginning of Period 443.0 428.9 439.5 422.8 422.8
Charge- Offs (20.1) (25.9) (43.0) (42.3)  
Recoveries 3.1 4.1 10.1 8.0  
Net (Charge- Offs) Recoveries (17.0) (21.8) (32.9) (34.3)  
Provision for Credit Losses 21.3 25.0 40.7 43.6  
Balance at End of Period 447.3 432.1 447.3 432.1 439.5
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 462.2 449.2 459.6 444.2 444.2
Charge- Offs (20.1) (25.9) (43.0) (42.3)  
Recoveries 3.1 4.1 10.1 8.0  
Net (Charge- Offs) Recoveries (17.0) (21.8) (32.9) (34.3)  
Provision for Credit Losses 21.2 25.7 39.7 43.2  
Balance at End of Period $ 466.4 $ 453.1 $ 466.4 $ 453.1 $ 459.6