Loans and Accounts Receivable (Details 4) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Impaired loans and receivables
Loans over 90 days past due and accruing interest	$ 366	$ 327
Non-accrual loans	217	199
Financing Receivable, Modifications, In-Program, Recorded Investment	314	261
Financing Receivable, Modifications, Out of Program, Recorded Investment	181	186
Total impaired loans and receivables	1,078	973
Unpaid principal balance	988	892
Related allowance for Troubled Debt Restructurings	64	60
Accounts Receivable and Loans Textuals [Abstract]
Total loans and receivables modified as a TDR, non-accrual	4	5
Total loans and receivables modified as a TDR, past due 90 days and still accruing	15	15
Financing Receivable, Modifications, Out of Program - success, Recorded Investment	137	141
Financing Receivable, Modifications, Out of Program - not compliant, Recorded Investment	44	45
U S Consumer Services [Member] | Card Member Loans [Member]
Impaired loans and receivables
Loans over 90 days past due and accruing interest	254	233
Non-accrual loans	182	168
Financing Receivable, Modifications, In-Program, Recorded Investment	209	178
Financing Receivable, Modifications, Out of Program, Recorded Investment	125	131
Total impaired loans and receivables	770	710
Unpaid principal balance	691	639
Related allowance for Troubled Debt Restructurings	52	49
U S Consumer Services [Member] | Card Member Receivables [Member]
Impaired loans and receivables
Loans over 90 days past due and accruing interest	0	0
Non-accrual loans	0	0
Financing Receivable, Modifications, In-Program, Recorded Investment	19	15
Financing Receivable, Modifications, Out of Program, Recorded Investment	10	9
Total impaired loans and receivables	29	24
Unpaid principal balance	29	24
Related allowance for Troubled Debt Restructurings	1	1
International Consumer and Network Services [Member] | Card Member Loans [Member]
Impaired loans and receivables
Loans over 90 days past due and accruing interest	66	56
Non-accrual loans	0	0
Financing Receivable, Modifications, In-Program, Recorded Investment	0	0
Financing Receivable, Modifications, Out of Program, Recorded Investment	0	0
Total impaired loans and receivables	66	56
Unpaid principal balance	65	55
Related allowance for Troubled Debt Restructurings	0	0
Global Commercial Services [Member] | Card Member Loans [Member]
Impaired loans and receivables
Loans over 90 days past due and accruing interest	46	38
Non-accrual loans	35	31
Financing Receivable, Modifications, In-Program, Recorded Investment	38	31
Financing Receivable, Modifications, Out of Program, Recorded Investment	25	27
Total impaired loans and receivables	144	127
Unpaid principal balance	134	118
Related allowance for Troubled Debt Restructurings	8	8
Global Commercial Services [Member] | Card Member Receivables [Member]
Impaired loans and receivables
Loans over 90 days past due and accruing interest	0	0
Non-accrual loans	0	0
Financing Receivable, Modifications, In-Program, Recorded Investment	48	37
Financing Receivable, Modifications, Out of Program, Recorded Investment	21	19
Total impaired loans and receivables	69	56
Unpaid principal balance	69	56
Related allowance for Troubled Debt Restructurings	$ 3	$ 2