Card Member Receivables and Card Member Loans (Details 3)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Global Consumer Services Group [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.04%	1.24%
Global Consumer Services Group [Member] | Card Member Receivables [Member] | 30 Days Past Due as a % of Total [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	0.94%	0.62%
Global Consumer Services Group [Member] | Card Member Loans [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.44%	0.93%
Global Consumer Services Group [Member] | Card Member Loans [Member] | 30 Days Past Due as a % of Total [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	0.93%	0.68%
Global Small Business Services [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.31%	1.51%
Global Small Business Services [Member] | Card Member Receivables [Member] | 30 Days Past Due as a % of Total [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.18%	0.86%
Global Corporate Payments [Member] | Card Member Receivables [Member] | Net Loss Ratio as a % of Charge Volume [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	0.06%	0.07%
Global Corporate Payments [Member] | Card Member Receivables [Member] | 90 Days Past Billing as a % of Receivables [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	0.66%	0.78%