Loans and Accounts Receivable (Details 5) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Impaired [Line Items]
Average balance of impaired loans	$ 884	$ 757	$ 760
Interest income recognized	102	81	73
U S Consumer Services [Member] | Card Member Loans [Member]
Financing Receivable Impaired [Line Items]
Average balance of impaired loans	643	559	569
Interest income recognized	68	53	48
U S Consumer Services [Member] | Card Member Receivables [Member]
Financing Receivable Impaired [Line Items]
Average balance of impaired loans	20	14	13
Interest income recognized	0	0	0
International Consumer and Network Services [Member] | Card Member Loans [Member]
Financing Receivable Impaired [Line Items]
Average balance of impaired loans	56	53	54
Interest income recognized	17	15	14
Global Commercial Services [Member] | Card Member Loans [Member]
Financing Receivable Impaired [Line Items]
Average balance of impaired loans	120	103	104
Interest income recognized	17	13	11
Global Commercial Services [Member] | Card Member Receivables [Member]
Financing Receivable Impaired [Line Items]
Average balance of impaired loans	45	28	20
Interest income recognized	$ 0	$ 0	$ 0