Loans and Card Member Receivables (Details 3)	Dec. 31, 2020	Dec. 31, 2019
Global Consumer Services Group [Member] | Card Member Loans [Member] | Net Write-Off Rate - Principal Only [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	2.50%	2.30%
Global Consumer Services Group [Member] | Card Member Loans [Member] | Net Write-Off Rate Principal Interest, and Fees [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	3.00%	2.80%
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	1.10%	1.60%
Global Consumer Services Group [Member] | Card Member Receivables [Member] | Net Write-Off Rate - Principal Only [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.70%	1.70%
Global Consumer Services Group [Member] | Card Member Receivables [Member] | Net Write-Off Rate Principal Interest, and Fees [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.90%	1.90%
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	0.60%	1.20%
Global Small Business Services [Member] | Card Member Loans [Member] | Net Write-Off Rate - Principal Only [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	2.10%	1.90%
Global Small Business Services [Member] | Card Member Loans [Member] | Net Write-Off Rate Principal Interest, and Fees [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	2.40%	2.20%
Global Small Business Services [Member] | Card Member Loans [Member] | 30 Days Past Due as a % of Total [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	0.70%	1.30%
Global Small Business Services [Member] | Card Member Receivables [Member] | Net Write-Off Rate - Principal Only [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	2.10%	1.90%
Global Small Business Services [Member] | Card Member Receivables [Member] | Net Write-Off Rate Principal Interest, and Fees [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	2.30%	2.10%
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	0.70%	1.70%
Global Corporate Payments [Member] | 90+ Days Past Billing As Percentage Of Receivables [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	0.60%	0.80%
Global Corporate Payments [Member] | Card Member Receivables [Member] | Net Write-Off Rate Principal Interest, and Fees [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	1.90%
Global Corporate Payments [Member] | Card Member Receivables [Member] | Net Loss Ratio As Percentage Of Charge Volume [Member]
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators		0.08%