v3.26.1
Business Combination - Loans Identified as PCI Loans at Acquisition (Details) - USD ($)
$ in Millions
 3 Months Ended
Feb. 01, 2026
Mar. 31, 2026
Mar. 31, 2025
Business Combination [Line Items]      
Adjustment for expected credit losses, PCD   $ 180  
Net charge-offs taken at time of acquisition   144 $ 136
Initial ALLL on other acquired loans and leases $ 8    
Comerica Incorporated      
Business Combination [Line Items]      
Fair value of acquired loans and leases, PCD 3,404    
Adjustment for expected credit losses, PCD 180    
Initial amortized cost basis of acquired loans and leases, PCD 3,584    
Unpaid principal balance of acquired loans and leases, PCD 3,680    
Noncredit discount, net, PCD 96    
Fair value of acquired loans and leases, PSL 46,066    
Adjustments for expected credit losses, PSL 481    
Initial amortized cost basis of acquired loans and leases, PSL 46,547    
Unpaid principal balance of acquired loans and leases, PSL 46,621    
Noncredit discount, net, PSL (74)    
Fair value of acquired loans and leases, Other 405    
Adjustment for expected credit losses, Other 0    
Unpaid principal balance of acquired loans and leases, Other 406    
Noncredit discount, net, Other (1)    
Fair value of acquired loans and leases, Total 49,875    
Adjustments for expected credit losses, Total 661    
Initial amortized cost basis of acquired loans and leases, Total 50,536    
Unpaid principal balance of acquired loans and leases, Total 50,707    
Noncredit discount, net, Total $ (171)    
Net charge-offs taken at time of acquisition   $ 94