Reportable Operating Segments and Geographic Operations (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Non-interest revenues		$ 7,877	$ 7,207
Revenue from contracts with customers	[1]	6,581	6,047
Interest income		2,462	1,945
Interest expense		621	443
Total revenues, net of interest expense		9,718	8,709
Net income		1,634	1,251
Total assets		179,956	161,000	$ 181,196
U S Consumer Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues		2,294	2,118
Revenue from contracts with customers	[1]	1,799	1,657
Interest income		1,656	1,310
Interest expense		253	161
Total revenues, net of interest expense		3,697	3,267
Net income		640	494
Total assets		94,000	85,000
International Consumer and Network Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues		1,551	1,400
Revenue from contracts with customers	[1]	1,093	1,009
Interest income		294	235
Interest expense		78	54
Total revenues, net of interest expense		1,767	1,581
Net income		291	252
Total assets		42,000	36,000
Global Commercial Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues		2,838	2,603
Revenue from contracts with customers	[1]	2,495	2,297
Interest income		377	319
Interest expense		171	123
Total revenues, net of interest expense		3,044	2,799
Net income		552	409
Total assets		58,000	52,000
Global Merchant Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues		1,110	1,021
Revenue from contracts with customers	[1]	1,110	1,021
Interest income		0	0
Interest expense		(63)	(43)
Total revenues, net of interest expense		1,173	1,064
Net income		472	357
Total assets		29,000	26,000
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Non-interest revenues		84	65
Revenue from contracts with customers	[1]	84	63
Interest income		135	81
Interest expense		182	148
Total revenues, net of interest expense		37	(2)
Net income		(321)	(261)
Total assets		$ (43,000)	$ (38,000)

[1] Includes discount revenue, certain other fees and commissions and other revenues from customers