Loans and Card Member Receivables - Credit Quality (Details)	Dec. 31, 2023	Dec. 31, 2022
Credit Quality Indicator for Loans and Receivables
90+ Days Past Billing as a % of total	0.40%	0.60%
Card Member loans | Consumer
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	1.40%	1.00%
Card Member loans | Small Business
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	1.40%	0.90%
Card Member loans | Net Write-Off Rate - Principal Only | Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	1.80%	0.90%
Card Member loans | Net Write-Off Rate - Principal Only | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	1.70%	0.70%
Card Member loans | Net Write-Off Rate Principal Interest, and Fees | Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.20%	1.20%
Card Member loans | Net Write-Off Rate Principal Interest, and Fees | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	1.90%	0.80%
Card Member receivables | Consumer
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	0.90%	1.10%
Card Member receivables | Small Business
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	1.40%	1.50%
Card Member receivables | Net Write-Off Rate - Principal Only | Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	1.50%	0.80%
Card Member receivables | Net Write-Off Rate - Principal Only | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.20%	1.10%
Card Member receivables | Net Write-Off Rate Principal Interest, and Fees | Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	1.60%	0.90%
Card Member receivables | Net Write-Off Rate Principal Interest, and Fees | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.40%	1.20%
Card Member receivables | Net Write-Off Rate Principal Interest, and Fees | Corporate
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	0.60%	0.40%