Reportable Operating Segements and Geographic Operations (Details 1) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense	$ 11,365	$ 10,989	$ 10,838	$ 10,364	$ 10,474	$ 10,144	$ 10,002	$ 9,718		$ 43,556	$ 40,338	$ 36,878
Pretax income	$ 1,986	$ 2,266	$ 2,219	$ 1,958	$ 1,831	$ 2,118	$ 2,091	$ 2,082		8,429	8,122	7,425
U.S. Tax Act discrete net charge									$ 2,600			2,600
United States [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense										32,557	29,864	27,187
Pretax income										7,262	6,696	6,412
EMEA [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense										4,465	4,419	3,927
Pretax income										1,243	1,212	1,150
JAPA Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense										3,915	3,656	3,464
Pretax income										833	764	763
LACC Geographic Region [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense										2,816	2,584	2,505
Pretax income										903	782	806
Other Unallocated [Member]
Segment Revenues And Pretax Income Loss By Geographic Location [Line Items]
Total revenues net of interest expense										(197)	(185)	(205)
Pretax income										$ (1,812)	$ (1,332)	$ (1,706)