Loans and Card Member Receivables (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Credit Quality Indicator for Loans and Receivables
90+ Days Past Billing as a % of total	0.60%	0.30%	0.60%	0.30%
Card Member Loans | Consumer
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	0.90%	0.70%	0.90%	0.70%
Card Member Loans | Small Business
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	0.70%	0.50%	0.70%	0.50%
Card Member Loans | Net Write-Off Rate - Principal Only | Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate			0.90%	1.10%
Card Member Loans | Net Write-Off Rate - Principal Only | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate			0.60%	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			1.10%	1.40%
Card Member Loans | Net Write-Off Rate Principal Interest, and Fees | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate			0.70%	0.80%
Card Member Receivables
Credit Quality Indicator for Loans and Receivables
Net write-offs (recovery)	$ 122	$ 32	$ 284	$ 89
Card Member Receivables | Consumer
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	1.00%	0.50%	1.00%	0.50%
Card Member Receivables | Small Business
Credit Quality Indicator for Loans and Receivables
30+ Days Past Due as a % of Total	1.30%	0.60%	1.30%	0.60%
Card Member Receivables | Corporate
Credit Quality Indicator for Loans and Receivables
Net write-offs (recovery)				$ 37
Card Member Receivables | Net Write-Off Rate - Principal Only | Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate			0.70%	0.30%
Card Member Receivables | Net Write-Off Rate - Principal Only | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate			0.90%	0.30%
Card Member Receivables | Net Write-Off Rate Principal Interest, and Fees | Consumer
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate			0.80%	0.40%
Card Member Receivables | Net Write-Off Rate Principal Interest, and Fees | Small Business
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate			1.00%	0.40%
Card Member Receivables | Net Write-Off Rate Principal Interest, and Fees | Corporate
Credit Quality Indicator for Loans and Receivables
Net Write-Off Rate			0.30%	(0.10%)