v3.26.3
Loans - Credit Card Loan Portfolio, Delinquency and Gross Charge-offs (Details) - USD ($)
$ in Millions
 9 Months Ended 12 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total retained loans $ 1,497,159 $ 1,369,785 $ 1,408,905
Total gross charge-offs 8,749 $ 8,941  
Credit card      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revolving loans within the revolving period 249,102   245,188
Revolving loans converted to term loans 3,595   2,609
Total retained loans $ 252,697   $ 247,797
% of 30 plus days past due to total retained loans, Revolving loans within the revolving period 1.85%   2.06%
% of 30 plus days past due to total retained loans, Revolving loans converted to term loans 10.68%   12.27%
% of 30 plus days past due to total retained loans 1.97%   2.16%
% of 90 plus days past due to total retained loans, Revolving loans within the revolving period 0.92%   1.07%
% of 90 plus days past due to total retained loans, Revolving loans converted to term loans 3.48%   4.33%
% of 90 plus days past due to total retained loans 0.96%   1.10%
Gross charge-offs originated within the revolving period $ 6,840   $ 8,812
Gross charge-offs originated converted to term loans 458   352
Total gross charge-offs 7,298   9,164
Credit card | Current and less than 30 days past due and still accruing      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revolving loans within the revolving period 244,504   240,147
Revolving loans converted to term loans 3,211   2,289
Total retained loans 247,715   242,436
Credit card | 30–89 days past due and still accruing      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revolving loans within the revolving period 2,302   2,422
Revolving loans converted to term loans 259   207
Total retained loans 2,561   2,629
Credit card | 90 or more days past due and still accruing      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Revolving loans within the revolving period 2,296   2,619
Revolving loans converted to term loans 125   113
Total retained loans $ 2,421   $ 2,732