Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Non-interest revenues
Discount revenue	$ 4,729	$ 4,482	$ 9,167	$ 8,739
Net card fees	647	615	1,300	1,225
Travel commissions and fees	495	521	932	972
Other commissions and fees	605	575	1,178	1,158
Other	567	651	1,104	1,204
Total non-interest revenues	7,043	6,844	13,681	13,298
Interest income
Interest on loans	1,622	1,582	3,305	3,193
Interest and dividends on investment securities	52	67	105	133
Deposits with banks and other	20	22	46	52
Total interest income	1,694	1,671	3,456	3,378
Interest expense
Deposits	107	115	221	244
Long-term debt and other	385	435	790	880
Total interest expense	492	550	1,011	1,124
Net interest income	1,202	1,121	2,445	2,254
Total revenues net of interest expense	8,245	7,965	16,126	15,552
Provisions for losses
Charge card	201	163	396	341
Cardmember loans	364	277	639	489
Other	28	21	55	43
Total provisions for losses	593	461	1,090	873
Total revenues net of interest expense after provisions for losses	7,652	7,504	15,036	14,679
Expenses
Marketing, promotion, rewards and cardmember services	2,580	2,415	4,910	4,707
Salaries and employee benefits	1,543	1,536	3,158	3,171
Other, net	1,534	1,674	3,064	3,149
Total expenses	5,657	5,625	11,132	11,027
Pretax income	1,995	1,879	3,904	3,652
Income tax provision	590	540	1,219	1,057
Net income	$ 1,405	$ 1,339	$ 2,685	$ 2,595
Earnings Per Common Share, Basic [Abstract]
Income from continuing operations attributable to common shareholders	$ 1.28	$ 1.16	$ 2.43	$ 2.23
Earnings Per Common Share, Diluted [Abstract]
Income from continuing operations attributable to common shareholders	$ 1.27	$ 1.15	$ 2.42	$ 2.22
Average common shares outstanding for earnings per common share:
Basic	1,090	1,145	1,094	1,151
Diluted	1,097	1,152	1,101	1,158
Cash dividends declared per common share	$ 0.23	$ 0.20	$ 0.43	$ 0.40