Reportable Operating Segments and Geographic Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Non-interest revenues	$ 8,183	$ 7,613	$ 24,233	$ 22,459
Revenue from contracts with customers	6,654	6,172	19,716	18,244
Interest income	2,738	2,245	7,740	6,244
Interest expense	777	568	2,109	1,532
Total revenues, net of interest expense	10,144	9,290	29,864	27,171
Net income	1,654	1,359	4,911	3,954
Total assets	189,092	169,000	189,092	169,000	$ 181,196
Global Consumer Services Group [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	3,680	3,361	10,849	9,843
Revenue from contracts with customers	2,577	2,359	7,611	6,922
Interest income	2,140	1,781	6,083	4,941
Interest expense	404	281	1,101	741
Total revenues, net of interest expense	5,416	4,861	15,831	14,043
Net income	779	680	2,375	1,968
Total assets	130,900	117,800	130,900	117,800
Global Commercial Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	2,980	2,734	8,795	8,076
Revenue from contracts with customers	2,593	2,365	7,628	6,980
Interest income	416	351	1,186	1,004
Interest expense	218	159	593	427
Total revenues, net of interest expense	3,178	2,926	9,388	8,653
Net income	606	505	1,716	1,387
Total assets	54,000	49,300	54,000	49,300
Global Merchant and Network Services [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	1,494	1,491	4,539	4,471
Revenue from contracts with customers	1,479	1,446	4,465	4,333
Interest income	6	8	22	32
Interest expense	(78)	(48)	(205)	(133)
Total revenues, net of interest expense	1,578	1,547	4,766	4,636
Net income	580	420	1,639	1,329
Total assets	31,900	27,900	31,900	27,900
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Non-interest revenues	29	27	50	69
Revenue from contracts with customers	5	2	12	9
Interest income	176	105	449	267
Interest expense	233	176	620	497
Total revenues, net of interest expense	(28)	(44)	(121)	(161)
Net income	(311)	(246)	(819)	(730)
Total assets	$ (27,800)	$ (26,000)	$ (27,800)	$ (26,000)