Card Balances and Other Loans - Credit Quality (Details)	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Credit Quality Indicator for Loans and Receivables
90+ Days Past Billing as a % of total	0.40%	0.40%
Card Balances \| Consumer
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	1.30%	1.30%
Card Balances \| Small Business
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	1.50%	1.40%
Card Balances \| Net Write-Off Rate - Principal Only \| Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	1.90%	2.10%
Card Balances \| Net Write-Off Rate - Principal Only \| Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.40%	2.30%
Card Balances \| Net Write-Off Rate Principal Interest, and Fees \| Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.30%	2.50%
Card Balances \| Net Write-Off Rate Principal Interest, and Fees \| Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.70%	2.60%
Card Balances \| Net Write-Off Rate Principal Interest, and Fees \| Corporate
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	0.70%	0.50%
Other Loans
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	0.60%	0.60%
Other Loans \| Net Write-Off Rate - Principal Only
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.00%	2.20%
Other Loans \| Net Write-Off Rate Principal Interest, and Fees
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate	2.10%	2.30%