Card Member Receivables and Loans (Details 3)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
U.S. Consumer Services [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0083	0.0054
U.S. Consumer Services [Member] | Card Member Receivables [Member] | 30 Days Past Due as a % of Total [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0073	0.0048
International Consumer and Network Services [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.015	0.0186
International Consumer and Network Services [Member] | Card Member Receivables [Member] | 30 Days Past Due as a % of Total [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.012	0.0131
International Consumer and Network Services [Member] | Card Member Loans [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0124	0.0115
International Consumer and Network Services [Member] | Card Member Loans [Member] | 30 Days Past Due as a % of Total [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0071	0.0084
Global Corporate Payments [Member] | Card Member Receivables [Member] | Net Loss Ratio as a % of Charge Volume [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0008	0.0006
Global Corporate Payments [Member] | Card Member Receivables [Member] | 90 days past billing as a percentage of receivables [Member}
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0083	0.009
Global Small Business Services [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0111	0.0103
Global Small Business Services [Member] | Card Member Receivables [Member] | 30 Days Past Due as a % of Total [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0106	0.0131