Card Member Receivables and Card Member Loans 2 (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Financing receivables gross	$ 12,157	$ 25,557
Global Consumer Services Group [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	2,139	9,766
Financing receivables gross	2,157	9,847
Global Consumer Services Group [Member] | Card Member Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	493	689
Financing receivables gross	500	697
Global Consumer Services Group [Member] | 30-59 Days Past Due [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	5	29
Global Consumer Services Group [Member] | 30-59 Days Past Due [Member] | Card Member Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	2	3
Global Consumer Services Group [Member] | 60-89 Days Past Due [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	4	16
Global Consumer Services Group [Member] | 60-89 Days Past Due [Member] | Card Member Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	1	2
Global Consumer Services Group [Member] | 90+ Days Past Due [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	9	36
Global Consumer Services Group [Member] | 90+ Days Past Due [Member] | Card Member Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	4	3
Global Small Business Services [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	1,047	1,996
Financing receivables gross	1,057	2,020
Global Small Business Services [Member] | 30-59 Days Past Due [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	3	10
Global Small Business Services [Member] | 60-89 Days Past Due [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	2	5
Global Small Business Services [Member] | 90+ Days Past Due [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	5	9
Global Corporate Payments [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Financing receivables gross	8,943	13,690
Global Corporate Payments [Member] | 90+ Days Past Due [Member] | Card Member Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Period past due	$ 32	$ 105