Card Balances and Other Loans - Credit Quality (Details)	9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025
Card Balances | Consumer
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	1.20%	1.30%
Card Balances | Small Business
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	1.30%	1.40%
Card Balances | Corporate
Credit Quality Indicator for Loans and Receivables
90+ Days Past Billing as a % of total	0.30%		0.40%
Card Balances | Net Write-Off Rate - Principal Only | Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	1.80%	1.90%
Card Balances | Net Write-Off Rate - Principal Only | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.30%	2.30%
Card Balances | Net Write-Off Rate Principal Interest, and Fees | Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.20%	2.40%
Card Balances | Net Write-Off Rate Principal Interest, and Fees | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.60%	2.60%
Card Balances | Net Write-Off Rate Principal Interest, and Fees | Corporate
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	0.60%	0.50%
Other Loans
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	0.50%	0.60%
Other Loans | Net Write-Off Rate - Principal Only
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.10%	2.00%
Other Loans | Net Write-Off Rate Principal Interest, and Fees
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.10%	2.10%