Reportable Operating Segments and Geographic Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Non-interest revenues	$ 6,861	$ 7,315	$ 13,364	$ 14,151
Interest income	1,837	1,759	3,694	3,535
Interest expense	414	443	824	882
Total revenues, net of interest expense	8,284	8,631	16,234	16,804
Net income	1,473	1,529	2,998	2,961
U S Card Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	3,372	3,196	6,520	6,187
Interest income	1,517	1,408	3,046	2,831
Interest expense	163	153	315	303
Total revenues, net of interest expense	4,726	4,451	9,251	8,715
Net income	886	770	1,820	1,646
International Card Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	1,082	1,208	2,143	2,365
Interest income	236	275	480	552
Interest expense	60	92	124	174
Total revenues, net of interest expense	1,258	1,391	2,499	2,743
Net income	125	77	259	236
Global Commercial Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	924	1,332	1,795	2,581
Interest income	3	3	7	7
Interest expense	46	66	94	125
Total revenues, net of interest expense	881	1,269	1,708	2,463
Net income	203	561	383	745
Global Network And Merchant Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	1,326	1,366	2,596	2,659
Interest income	23	11	43	21
Interest expense	(47)	(78)	(101)	(140)
Total revenues, net of interest expense	1,396	1,455	2,740	2,820
Net income	448	373	892	816
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	157	213	310	359
Interest income	58	62	118	124
Interest expense	192	210	392	420
Total revenues, net of interest expense	23	65	36	63
Net income	$ (189)	$ (252)	$ (356)	$ (482)