Loans and Card Member Receivables (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Card Member Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 109,050	$ 107,964
Less: Reserves for credit losses	4,053	3,747	$ 2,981	$ 3,305
Financing receivables, net	104,997	104,217
Card Member Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	84,248	84,964
Card Member Loans | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	24,717	22,947
Card Member Loans | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	85	53
Other Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: Reserves for credit losses	83	59
Financing receivables, net	5,818	5,357
Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	57,494	57,613
Less: Reserves for credit losses	223	229	$ 76	$ 64
Financing receivables, net	57,271	57,384
Card Member Receivables | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	21,725	22,885
Card Member Receivables | Small Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	19,546	19,629
Card Member Receivables | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	16,223	15,099
Variable Interest Entity, Primary Beneficiary | Card Member Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	27,098	28,461
Variable Interest Entity, Primary Beneficiary | Card Member Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	27,100	28,500
Variable Interest Entity, Primary Beneficiary | Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	5,336	5,193
Variable Interest Entity, Primary Beneficiary | Card Member Receivables | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 5,300	$ 5,200