Loans and Accounts Receivable (Details 3)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
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	0.021	0.018
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	0.025	0.021
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	0.013	0.012
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	0.016	0.016
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	0.018	0.018
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	0.012	0.012
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	0.0011	0.001
Global Corporate Payments [Member] | Card Member Receivables [Member] | 90 days past billing as a percentage of receivables [Member}
Credit Quality Indicator for Loans and Receivables
Credit Quality Indicators	0.008	0.008
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	0.017	0.015
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	0.02	0.018
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	0.012	0.011
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	0.019	0.017
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	0.021	0.019
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	0.014	0.014