Card Member Receivables and Card Member Loans (Details 3)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Global Consumer Services Group [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.45%	1.11%
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	1.89%	0.65%
Global Consumer Services Group [Member] | Card Member Loans [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	2.03%	1.55%
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	2.18%	0.90%
Global Small Business Services [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	2.13%	1.36%
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	1.39%	0.94%
Global Corporate Payments [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.26%
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%
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	1.98%	0.66%