Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Non-interest revenues
Discount revenue	$ 4,438	$ 4,257
Net card fees	653	610
Travel commissions and fees	437	451
Other commissions and fees	573	583
Other	537	553
Total non-interest revenues	6,638	6,454
Interest income
Interest on loans	1,683	1,611
Interest and dividends on investment securities	53	66
Deposits with banks and other	26	30
Total interest income	1,762	1,707
Interest expense
Deposits	114	129
Long-term debt and other	405	445
Total interest expense	519	574
Net interest income	1,243	1,133
Total revenues net of interest expense	7,881	7,587
Provisions for losses
Charge card	195	178
Cardmember loans	275	212
Other	27	22
Total provisions for losses	497	412
Total revenues net of interest expense after provisions for losses	7,384	7,175
Expenses
Marketing, promotion, rewards and cardmember services	2,330	2,292
Salaries and employee benefits	1,615	1,635
Other, net	1,530	1,475
Total expenses	5,475	5,402
Pretax income	1,909	1,773
Income tax provision	629	517
Income from continuing operations	$ 1,280	$ 1,256
Earnings Per Share, Basic [Abstract]
Net income attributable to common shareholders	$ 1.15	$ 1.07
Earnings Per Share, Diluted [Abstract]
Income from continuing operations attributable to common shareholders	$ 1.15	$ 1.07
Average common shares outstanding for earnings per common share:
Basic	1,099	1,160
Diluted	1,106	1,166
Cash dividends declared per common share	$ 0.20	$ 0.20