Reportable Operating Segments and Geographic Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Non-interest revenues									$ 28,102	$ 34,936	$ 32,675
Revenue from contracts with customers									21,974	28,159	26,607
Interest income									10,083	12,084	10,606
Interest expense									2,098	3,464	2,943
Total revenues, net of interest expense	$ 9,351	$ 8,751	$ 7,675	$ 10,310	$ 11,365	$ 10,989	$ 10,838	$ 10,364	36,087	43,556	40,338
Net income (loss)	1,438	$ 1,073	$ 257	$ 367	1,693	$ 1,755	$ 1,761	$ 1,550	3,135	6,759	6,921
Total assets	191,367				198,321				191,367	198,321	189,000
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Non-interest revenues									(323)	89	47
Revenue from contracts with customers									(27)	5	12
Interest income									280	743	632
Interest expense									508	1,003	841
Total revenues, net of interest expense									(551)	(171)	(162)
Net income (loss)									(1,256)	(1,371)	(616)
Total assets	48,000				21,000				48,000	21,000	20,000
Global Consumer Services Group [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Non-interest revenues									14,178	16,702	15,357
Revenue from contracts with customers									9,536	12,097	11,264
Interest income									8,199	9,413	8,323
Interest expense									1,051	1,730	1,448
Total revenues, net of interest expense									21,326	24,385	22,232
Net income (loss)									2,701	3,807	3,615
Total assets	87,000				106,000				87,000	106,000	102,000
Global Commercial Services [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Non-interest revenues									9,652	12,242	11,481
Revenue from contracts with customers									8,145	10,633	10,019
Interest income									1,586	1,900	1,621
Interest expense									619	1,034	898
Total revenues, net of interest expense									10,619	13,108	12,204
Net income (loss)									736	2,191	2,012
Total assets	42,000				53,000				42,000	53,000	51,000
Global Merchant and Network Services [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Non-interest revenues									4,595	5,903	5,790
Revenue from contracts with customers									4,320	5,424	5,312
Interest income									18	28	30
Interest expense									(80)	(303)	(244)
Total revenues, net of interest expense									4,693	6,234	6,064
Net income (loss)									954	2,132	1,910
Total assets	$ 14,000				$ 18,000				$ 14,000	$ 18,000	$ 16,000