Card Member Receivables and Card Member Loans (Details 2) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 12,868	$ 12,157
Global Consumer Services Group | Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	2,169	2,157
Global Consumer Services Group | Card Member Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	479	500
Global Consumer Services Group | Current | Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	2,157	2,139
Global Consumer Services Group | Current | Card Member Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	474	493
Global Consumer Services Group | 30-59 Days Past Due | Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	3	5
Global Consumer Services Group | 30-59 Days Past Due | Card Member Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	1	2
Global Consumer Services Group | 60-89 Days Past Due | Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	2	4
Global Consumer Services Group | 60-89 Days Past Due | Card Member Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	1	1
Global Consumer Services Group | 90+ Days Past Due | Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	7	9
Global Consumer Services Group | 90+ Days Past Due | Card Member Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	3	4
Global Commercial Services | Card Member Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	10,699	10,000
Global Commercial Services | Card Member Receivables | Global Small Business Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	1,109	1,057
Global Commercial Services | Card Member Receivables | Global Corporate Payments
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	9,590	8,943
Global Commercial Services | Current | Card Member Receivables | Global Small Business Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	1,101	1,047
Global Commercial Services | 30-59 Days Past Due | Card Member Receivables | Global Small Business Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	3	3
Global Commercial Services | 60-89 Days Past Due | Card Member Receivables | Global Small Business Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	1	2
Global Commercial Services | 90+ Days Past Due | Card Member Receivables | Global Small Business Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	4	5
Global Commercial Services | 90+ Days Past Due | Card Member Receivables | Global Corporate Payments
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables, gross	$ 24	$ 32