v3.26.1
Segments - Operating Segment Information (Detail)
$ in Millions
 3 Months Ended
Mar. 31, 2026
USD ($)
Segment
Mar. 31, 2025
USD ($)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Operating Statistics [Line Items]        
Reportable segments | Segment 3      
Goodwill weighting assigned 100.00%      
Cash, cash equivalents, and investment securities $ 28,946.0   $ 24,034.0  
Loans HFS 3,936.0   3,498.0  
Loans HFI, net of deferred fees and costs 59,142.0   58,677.0  
Less: allowance for credit losses (461.1) $ (388.6) (460.6) $ (373.8)
Net loans HFI 58,681.0   58,216.0  
Goodwill and intangible assets, net 646.0   649.0  
Other assets 6,644.0   6,377.0  
Total assets 98,853.0   92,774.0  
Total deposits 82,723.0   77,159.0  
Borrowings and qualifying debt 6,682.0   6,316.0  
Other liabilities 1,540.0   1,353.0  
Total liabilities 90,945.0   84,828.0  
Total equity 7,908.1 7,214.5 7,945.9 $ 6,707.5
Total liabilities and equity 98,853.0   92,774.0  
Excess funds (used) provided 0.0   0.0  
Interest income 1,188.2 1,095.6    
Interest expense 421.9 445.0    
Funds transfer pricing 0.0 0.0    
Net interest income 766.3 650.6    
Provision for (recovery of) credit losses 213.2 31.2    
Net interest income (expense) after provision for credit losses 553.1 619.4    
Non-interest income 252.6 127.4    
Salaries and employee benefits 205.5 182.4    
Other non-interest expense 368.9 318.0    
Income (loss) before provision for income taxes 231.3 246.4    
Income tax expense (benefit) 42.1 47.3    
Net income $ 189.2 199.1    
Minimum        
Operating Statistics [Line Items]        
Equity capital weighting assigned 0.00%      
Maximum        
Operating Statistics [Line Items]        
Equity capital weighting assigned 25.00%      
Operating Segments | Commercial Segment        
Operating Statistics [Line Items]        
Cash, cash equivalents, and investment securities $ 13.0   16.0  
Loans HFS 65.0   67.0  
Loans HFI, net of deferred fees and costs 35,234.0   34,784.0  
Less: allowance for credit losses (389.0)   (390.0)  
Net loans HFI 34,845.0   34,394.0  
Goodwill and intangible assets, net 290.0   290.0  
Other assets 368.0   352.0  
Total assets 35,581.0   35,119.0  
Total deposits 31,096.0   30,806.0  
Borrowings and qualifying debt 0.0   0.0  
Other liabilities 97.0   91.0  
Total liabilities 31,193.0   30,897.0  
Total equity 3,645.0   3,400.0  
Total liabilities and equity 34,838.0   34,297.0  
Excess funds (used) provided (743.0)   (822.0)  
Interest income 598.5 591.5    
Interest expense 158.3 149.9    
Funds transfer pricing (69.7) (131.7)    
Net interest income 370.5 309.9    
Provision for (recovery of) credit losses 206.3 31.3    
Net interest income (expense) after provision for credit losses 164.2 278.6    
Non-interest income 47.8 36.9    
Salaries and employee benefits 44.0 44.2    
Other non-interest expense 138.7 124.7    
Income (loss) before provision for income taxes 29.3 146.6    
Income tax expense (benefit) 5.0 22.4    
Net income 24.3 124.2    
Operating Segments | Consumer Related Segment        
Operating Statistics [Line Items]        
Cash, cash equivalents, and investment securities 0.0   0.0  
Loans HFS 3,871.0   3,431.0  
Loans HFI, net of deferred fees and costs 23,908.0   23,893.0  
Less: allowance for credit losses (72.0)   (71.0)  
Net loans HFI 23,836.0   23,822.0  
Goodwill and intangible assets, net 356.0   359.0  
Other assets 2,414.0   2,237.0  
Total assets 30,477.0   29,849.0  
Total deposits 45,923.0   40,466.0  
Borrowings and qualifying debt 24.0   48.0  
Other liabilities 418.0   336.0  
Total liabilities 46,365.0   40,850.0  
Total equity 2,688.0   2,570.0  
Total liabilities and equity 49,053.0   43,420.0  
Excess funds (used) provided 18,576.0   13,571.0  
Interest income 329.9 285.2    
Interest expense 150.7 156.0    
Funds transfer pricing 305.4 270.1    
Net interest income 484.6 399.3    
Provision for (recovery of) credit losses 6.4 5.0    
Net interest income (expense) after provision for credit losses 478.2 394.3    
Non-interest income 118.4 79.5    
Salaries and employee benefits 50.8 43.1    
Other non-interest expense 322.0 266.7    
Income (loss) before provision for income taxes 223.8 164.0    
Income tax expense (benefit) 39.5 25.2    
Net income 184.3 138.8    
Corporate & Other | Corporate And Other Segment        
Operating Statistics [Line Items]        
Cash, cash equivalents, and investment securities 28,933.0   24,018.0  
Loans HFS 0.0   0.0  
Loans HFI, net of deferred fees and costs 0.0   0.0  
Less: allowance for credit losses 0.0   0.0  
Net loans HFI 0.0   0.0  
Goodwill and intangible assets, net 0.0   0.0  
Other assets 3,862.0   3,788.0  
Total assets 32,795.0   27,806.0  
Total deposits 5,704.0   5,887.0  
Borrowings and qualifying debt 6,658.0   6,268.0  
Other liabilities 1,025.0   926.0  
Total liabilities 13,387.0   13,081.0  
Total equity 1,575.0   1,976.0  
Total liabilities and equity 14,962.0   15,057.0  
Excess funds (used) provided (17,833.0)   $ (12,749.0)  
Interest income 259.8 218.9    
Interest expense 112.9 139.1    
Funds transfer pricing (235.7) (138.4)    
Net interest income (88.8) (58.6)    
Provision for (recovery of) credit losses 0.5 (5.1)    
Net interest income (expense) after provision for credit losses (89.3) (53.5)    
Non-interest income 86.4 11.0    
Salaries and employee benefits 110.7 95.1    
Other non-interest expense (91.8) (73.4)    
Income (loss) before provision for income taxes (21.8) (64.2)    
Income tax expense (benefit) (2.4) (0.3)    
Net income $ (19.4) $ (63.9)