Card Member Receivables and Card Member Loans (Details 2) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables total aging	$ 10,987	$ 25,557
Global Consumer Services Group [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Current	1,714	9,766
Card Member receivables total aging	1,733	9,847
Global Consumer Services Group [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Current	445	689
Card Member loans total aging	453	697
Global Consumer Services Group [Member] | 30-59 Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	7	29
Global Consumer Services Group [Member] | 30-59 Days Past Due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
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
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
Period past due	1	2
Global Consumer Services Group [Member] | 90+ Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	8	36
Global Consumer Services Group [Member] | 90+ Days Past Due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	5	3
Global Small Business Services [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Current	913	1,996
Card Member receivables total aging	923	2,020
Global Small Business Services [Member] | 30-59 Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	5	10
Global Small Business Services [Member] | 60-89 Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	2	5
Global Small Business Services [Member] | 90+ Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	3	9
Global Corporate Payments [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables total aging	8,331	13,690
Global Corporate Payments [Member] | 90+ Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	$ 53	$ 105