Reportable Operating Segments and Geographic Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Non-interest revenues	$ 8,173	$ 7,639	$ 16,050	$ 14,846
Revenue from contracts with customers	6,674	6,224	13,061	12,072
Interest income	2,540	2,054	5,002	3,999
Interest expense	711	521	1,332	964
Total revenues, net of interest expense	10,002	9,172	19,720	17,881
Net income	1,623	1,344	3,257	2,595
Total assets	184,861	167,000	184,861	167,000	$ 181,196
Global Consumer Services Group [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	3,678	3,345	7,169	6,482
Revenue from contracts with customers	2,596	2,368	5,034	4,564
Interest income	1,994	1,616	3,943	3,160
Interest expense	370	247	697	460
Total revenues, net of interest expense	5,302	4,714	10,415	9,182
Net income	770	615	1,596	1,288
Total assets	126,800	112,700	126,800	112,700
Global Commercial Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	2,977	2,738	5,815	5,342
Revenue from contracts with customers	2,581	2,372	5,034	4,614
Interest income	393	334	770	653
Interest expense	204	145	375	268
Total revenues, net of interest expense	3,166	2,927	6,210	5,727
Net income	564	477	1,110	882
Total assets	52,900	47,300	52,900	47,300
Global Merchant and Network Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	1,513	1,518	3,045	2,980
Revenue from contracts with customers	1,495	1,481	2,986	2,888
Interest income	7	9	16	24
Interest expense	(68)	(47)	(127)	(85)
Total revenues, net of interest expense	1,588	1,574	3,188	3,089
Net income	543	476	1,059	909
Total assets	31,300	26,800	31,300	26,800
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	5	38	21	42
Revenue from contracts with customers	2	3	7	6
Interest income	146	95	273	162
Interest expense	205	176	387	321
Total revenues, net of interest expense	(54)	(43)	(93)	(117)
Net income	(254)	(224)	(508)	(484)
Total assets	$ (26,000)	$ (19,800)	$ (26,000)	$ (19,800)