Card Member Receivables and Card Member Loans 3 (Details)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Global Consumer Services Group [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.012	0.0125
Global Consumer Services Group [Member] | Card Member Receivables [Member] | 30+ Days Past Due as a % of Total [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.007	0.01
Global Consumer Services Group [Member] | Card Member Loans [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0125	0.014
Global Consumer Services Group [Member] | Card Member Loans [Member] | 30+ Days Past Due as a % of Total [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0078	0.0089
Global Small Business Services [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Receivables and Loans
Credit Quality Indicators	0.0147	0.0142
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	0.01	0.013
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	0.0006	0.0007
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	0.0063	0.0086