Loans and Accounts Receivable (Details 2) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financing receivable recorded investment aging
Card Member receivables Total Aging	$ 54,047	$ 47,308
Card Member loans total aging	73,399	65,265
U S Consumer Services [Member]
Financing receivable recorded investment aging
Card Member receivables Total Aging	13,143	12,302
Card Member loans total aging	53,668	48,758
U S Consumer Services [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Current	52,961	48,216
U S Consumer Services [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Current	12,993	12,158
U S Consumer Services [Member] | 30 to 59 [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	201	156
U S Consumer Services [Member] | 30 to 59 [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	53	45
U S Consumer Services [Member] | 60 to 89 [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	162	119
U S Consumer Services [Member] | 60 to 89 [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	33	30
U S Consumer Services [Member] | 90+ days past due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	344	267
U S Consumer Services [Member] | 90+ days past due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	64	69
International Consumer and Network Services [Member]
Financing receivable recorded investment aging
Card Member receivables Total Aging	7,803	5,966
Card Member loans total aging	8,651	6,971
International Consumer and Network Services [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Current	8,530	6,863
International Consumer and Network Services [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Current	7,703	5,888
International Consumer and Network Services [Member] | 30 to 59 [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	37	32
International Consumer and Network Services [Member] | 30 to 59 [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	29	22
International Consumer and Network Services [Member] | 60 to 89 [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	28	24
International Consumer and Network Services [Member] | 60 to 89 [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	21	15
International Consumer and Network Services [Member] | 90+ days past due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	56	52
International Consumer and Network Services [Member] | 90+ days past due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	50	41
Global Commercial Services [Member]
Financing receivable recorded investment aging
Card Member receivables Total Aging	33,101	29,040
Card Member loans total aging	11,080	9,536
Global Small Business Services [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Current	10,892	9,378
Card Member receivables Total Aging	11,025	9,484
Global Small Business Services [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Current	15,868	14,047
Card Member loans total aging	16,119	14,273
Global Small Business Services [Member] | 30 to 59 [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	43	34
Global Small Business Services [Member] | 30 to 59 [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	91	77
Global Small Business Services [Member] | 60 to 89 [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	31	23
Global Small Business Services [Member] | 60 to 89 [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	54	47
Global Small Business Services [Member] | 90+ days past due [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Period past due	59	49
Global Small Business Services [Member] | 90+ days past due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	106	102
Global Corporate Payments [Member] | Card Member Loans [Member]
Financing receivable recorded investment aging
Card Member receivables Total Aging	55	52
Global Corporate Payments [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Card Member loans total aging	16,982	14,767
Global Corporate Payments [Member] | 90+ days past due [Member] | Card Member Receivables [Member]
Financing receivable recorded investment aging
Period past due	$ 148	$ 135