Loans and Card Member Receivables - Card Member and other Loans (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Card Member loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 151,832	$ 139,674
Financing receivables, reserves for credit losses	5,909	5,679	$ 5,118	$ 3,747
Financing receivables, net	145,923	133,995
Card Member loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	117,719	107,646
Card Member loans | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	34,074	31,991
Card Member loans | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	39	37
Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	10,928	9,232
Financing receivables, reserves for credit losses	323	194	$ 126	$ 59
Financing receivables, net	10,605	9,038
Variable Interest Entity, Primary Beneficiary | Card Member loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	27,719	28,278
Variable Interest Entity, Primary Beneficiary | Card Member loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 27,700	$ 28,300