Loans and Accounts Receivable (Details 2) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing receivable recorded investment aging
Card member loans	$ 87,381	$ 81,854
Card Member receivables	57,413	55,893
Global Consumer Services Group [Member]
Financing receivable recorded investment aging
Card member loans	73,266	69,458
Card Member receivables	22,844	21,455
Global Consumer Services Group [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	73,266	69,458
Global Consumer Services Group [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	22,844	21,455
Global Consumer Services Group [Member] | Financial Receivables, Current [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	72,101	68,442
Global Consumer Services Group [Member] | Financial Receivables, Current [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	22,560	21,207
Global Consumer Services Group [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	322	290
Global Consumer Services Group [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	86	80
Global Consumer Services Group [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	253	220
Global Consumer Services Group [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	58	50
Global Consumer Services Group [Member] | 90+ days past due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	590	506
Global Consumer Services Group [Member] | 90+ days past due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	140	118
Global Small Business Services [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	14,079	12,351
Global Small Business Services [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	17,404	16,728
Global Small Business Services [Member] | Financial Receivables, Current [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	13,898	12,195
Global Small Business Services [Member] | Financial Receivables, Current [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	17,113	16,460
Global Small Business Services [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	56	51
Global Small Business Services [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	99	101
Global Small Business Services [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	40	32
Global Small Business Services [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	58	53
Global Small Business Services [Member] | 90+ days past due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	85	73
Global Small Business Services [Member] | 90+ days past due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	134	114
Global Corporate Payments [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card member loans	36	45
Global Corporate Payments [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	17,165	17,710
Global Corporate Payments [Member] | 90+ days past due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member receivables	$ 136	$ 129