Card Member Receivables and Card Member Loans (Details 3)	9 Months Ended
	Sep. 30, 2020	Sep. 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	1.62%	1.04%
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	1.10%	0.94%
Global Consumer Services Group [Member] | Card Member Loans [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	2.66%	1.44%
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	1.77%	0.93%
Global Small Business Services [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	2.14%	1.31%
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	1.08%	1.18%
Global Corporate Payments [Member] | Card Member Receivables [Member] | Net Write-Off Rate [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.49%
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	0.64%	0.66%