Loans and Card Member Receivables (Details 2) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Financing receivable recorded investment aging
Card Member loans total aging	$ 70,059	$ 87,381
Card Member receivables total aging	37,553	57,413
Global Consumer Services Group [Member]
Financing receivable recorded investment aging
Card Member loans total aging	57,907	73,266
Card Member receivables total aging	14,977	22,844
Global Consumer Services Group [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Current	56,959	72,101
Card Member loans total aging	57,907	73,266
Global Consumer Services Group [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Current	14,778	22,560
Card Member receivables total aging	14,977	22,844
Global Consumer Services Group [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	240	322
Global Consumer Services Group [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	51	86
Global Consumer Services Group [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	202	253
Global Consumer Services Group [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	37	58
Global Consumer Services Group [Member] | 90+ days past due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	506	590
Global Consumer Services Group [Member] | 90+ days past due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	111	140
Global Commercial Services [Member]
Financing receivable recorded investment aging
Card Member loans total aging	12,152	14,115
Card Member receivables total aging	22,576	34,569
Global Commercial Services [Member] | Card Member Loans [Member] | Global Small Business Services [Member]
Financing receivable recorded investment aging
Current	11,894	13,898
Card Member loans total aging	12,089	14,079
Global Commercial Services [Member] | Card Member Loans [Member] | Global Corporate Payments [Member]
Financing receivable recorded investment aging
Card Member loans total aging	63	36
Global Commercial Services [Member] | Card Member Receivables [Member] | Global Small Business Services [Member]
Financing receivable recorded investment aging
Current	12,904	17,113
Card Member receivables total aging	13,174	17,404
Global Commercial Services [Member] | Card Member Receivables [Member] | Global Corporate Payments [Member]
Financing receivable recorded investment aging
Card Member receivables total aging	9,402	17,165
Global Commercial Services [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Card Member Loans [Member] | Global Small Business Services [Member]
Financing receivable recorded investment aging
Period past due	69	56
Global Commercial Services [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Card Member Receivables [Member] | Global Small Business Services [Member]
Financing receivable recorded investment aging
Period past due	103	99
Global Commercial Services [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Card Member Loans [Member] | Global Small Business Services [Member]
Financing receivable recorded investment aging
Period past due	42	40
Global Commercial Services [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Card Member Receivables [Member] | Global Small Business Services [Member]
Financing receivable recorded investment aging
Period past due	48	58
Global Commercial Services [Member] | 90+ days past due [Member] | Card Member Loans [Member] | Global Small Business Services [Member]
Financing receivable recorded investment aging
Period past due	84	85
Global Commercial Services [Member] | 90+ days past due [Member] | Card Member Loans [Member] | Global Corporate Payments [Member]
Financing receivable recorded investment aging
Period past due	0	0
Global Commercial Services [Member] | 90+ days past due [Member] | Card Member Receivables [Member] | Global Small Business Services [Member]
Financing receivable recorded investment aging
Period past due	119	134
Global Commercial Services [Member] | 90+ days past due [Member] | Card Member Receivables [Member] | Global Corporate Payments [Member]
Financing receivable recorded investment aging
Period past due	$ 235	$ 136