v3.26.1
Loans and Related Allowance for Credit Losses (Credit Quality Indicators for Automobile, Credit Card, Education and Other Consumer Loan Classes) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Total loans, net [1] $ 360,923   $ 331,481
Gross charge-offs      
Total 309 $ 312  
Automobile      
Gross charge-offs      
Year one 0   9
Year two 9   38
Year three 8   39
Year four 8   20
Year five 3   11
Prior 3   13
Revolving Loans 0   0
Revolving Loans Converted to Term 0   0
Total 31   130
Automobile | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 1,687   7,754
Year two 7,055   4,227
Year three 3,742   2,310
Year four 2,000   1,296
Year five 1,092   769
Prior 749   235
Revolving Loans 0   0
Revolving Loans Converted to Term 0   0
Total loans, net 16,325   16,591
Automobile | Greater than or equal to 780 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 1,135   4,241
Year two 3,487   1,991
Year three 1,735   1,022
Year four 862   608
Year five 500   387
Prior 347   85
Revolving Loans 0   0
Revolving Loans Converted to Term 0   0
Total loans, net 8,066   8,334
Automobile | 720 to 779 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 416   2,394
Year two 2,296   1,216
Year three 1,061   609
Year four 523   322
Year five 272   178
Prior 171   52
Revolving Loans 0   0
Revolving Loans Converted to Term 0   0
Total loans, net 4,739   4,771
Automobile | 660 to 719 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 124   883
Year two 958   668
Year three 597   387
Year four 341   199
Year five 169   104
Prior 107   39
Revolving Loans 0   0
Revolving Loans Converted to Term 0   0
Total loans, net 2,296   2,280
Automobile | Less than 660 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 12   236
Year two 314   352
Year three 349   292
Year four 274   167
Year five 151   100
Prior 124   59
Revolving Loans 0   0
Revolving Loans Converted to Term 0   0
Total loans, net 1,224   1,206
Credit card      
Gross charge-offs      
Year one 0   0
Year two 0   0
Year three 0   0
Year four 0   0
Year five 0   0
Prior 0   0
Revolving Loans 64   280
Revolving Loans Converted to Term 10   40
Total 74   320
Credit card | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 0   0
Year two 0   0
Year three 0   0
Year four 0   0
Year five 0   0
Prior 0   0
Revolving Loans 6,991   6,933
Revolving Loans Converted to Term 78   81
Total loans, net 7,069   7,014
Credit card | Greater than or equal to 780 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 0   0
Year two 0   0
Year three 0   0
Year four 0   0
Year five 0   0
Prior 0   0
Revolving Loans 2,210   2,199
Revolving Loans Converted to Term 1   1
Total loans, net 2,211   2,200
Credit card | 720 to 779 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 0   0
Year two 0   0
Year three 0   0
Year four 0   0
Year five 0   0
Prior 0   0
Revolving Loans 1,890   1,903
Revolving Loans Converted to Term 5   6
Total loans, net 1,895   1,909
Credit card | 660 to 719 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 0   0
Year two 0   0
Year three 0   0
Year four 0   0
Year five 0   0
Prior 0   0
Revolving Loans 1,845   1,813
Revolving Loans Converted to Term 17   17
Total loans, net 1,862   1,830
Credit card | Less than 660 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 0   0
Year two 0   0
Year three 0   0
Year four 0   0
Year five 0   0
Prior 0   0
Revolving Loans 922   922
Revolving Loans Converted to Term 53   55
Total loans, net 975   977
Credit card | No FICO score available or required | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 0   0
Year two 0   0
Year three 0   0
Year four 0   0
Year five 0   0
Prior 0   0
Revolving Loans 124   96
Revolving Loans Converted to Term 2   2
Total loans, net 126   98
Other consumer      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 217   914
Year two 832   531
Year three 462   308
Year four 273   217
Year five 186   85
Prior 1,191   1,149
Revolving Loans 2,611   2,501
Revolving Loans Converted to Term 7   7
Total loans, net 5,779   5,712
Gross charge-offs      
Year one 22   81
Year two 5   24
Year three 5   24
Year four 4   14
Year five 2   5
Prior 4   14
Revolving Loans 3   10
Revolving Loans Converted to Term 0   1
Total 45   173
Other consumer | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 217   908
Year two 826   526
Year three 457   290
Year four 244   210
Year five 179   75
Prior 480   446
Revolving Loans 193   205
Revolving Loans Converted to Term 0   0
Total loans, net 2,596   2,660
Other consumer | Greater than or equal to 780 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 58   301
Year two 275   168
Year three 141   108
Year four 90   93
Year five 81   39
Prior 298   282
Revolving Loans 31   34
Revolving Loans Converted to Term 0   0
Total loans, net 974   1,025
Other consumer | 720 to 779 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 73   324
Year two 293   175
Year three 147   90
Year four 75   58
Year five 49   20
Prior 109   98
Revolving Loans 60   64
Revolving Loans Converted to Term 0   0
Total loans, net 806   829
Other consumer | 660 to 719 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 72   230
Year two 197   133
Year three 119   62
Year four 53   38
Year five 32   10
Prior 49   44
Revolving Loans 66   70
Revolving Loans Converted to Term 0   0
Total loans, net 588   587
Other consumer | Less than 660 | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 10   48
Year two 55   45
Year three 45   27
Year four 24   20
Year five 16   6
Prior 24   22
Revolving Loans 36   37
Revolving Loans Converted to Term 0   0
Total loans, net 210   205
Other consumer | No FICO score available or required | Using FICO Credit Metric      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 4   5
Year two 6   5
Year three 5   3
Year four 2   1
Year five 1   0
Prior 0   0
Revolving Loans 0   0
Revolving Loans Converted to Term 0   0
Total loans, net 18   14
Other consumer | Other internal credit metrics      
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]      
Year one 0   6
Year two 6   5
Year three 5   18
Year four 29   7
Year five 7   10
Prior 711   703
Revolving Loans 2,418   2,296
Revolving Loans Converted to Term 7   7
Total loans, net $ 3,183   $ 3,052
[1] Our consolidated assets included the following for which we have elected the fair value option: Loans held for sale of $1.2 billion, Loans held for investment of $1.1 billion and Other assets of $0.1 billion at March 31, 2026. Comparable amounts at December 31, 2025 were $1.7 billion, $1.1 billion and $0.2 billion, respectively.