Loans and Card Member Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Card Member loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 88,562	$ 73,373
Financing receivables, reserves for credit losses	3,305	5,344	$ 2,383	$ 2,134
Financing receivables, net	85,257	68,029
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, reserves for credit losses	52	238
Financing receivables, net	2,859	2,614
Other | PPP Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	36	630
Variable Interest Entity, Primary Beneficiary | Card Member loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	26,587	25,908
Global Consumer Services Group | Card Member loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	70,467	60,084
Global Commercial Services | Card Member loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 18,095	$ 13,289