Business Segment Information - Business Segment Reconciliations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segments’ total revenue, net of interest expense (FTE basis)
Total revenue, net of interest expense (FTE basis)	$ 23,275	$ 22,445
Total revenue, net of interest expense	23,125	22,248
Net income	6,918	5,337
Operating Segments
Segments’ total revenue, net of interest expense (FTE basis)
Total revenue, net of interest expense (FTE basis)	23,608	22,539
Net income	7,204	5,691
ALM activities
Segments’ total revenue, net of interest expense (FTE basis)
Total revenue, net of interest expense	116	(45)
Net income	(54)	(179)
Liquidating businesses and other
Segments’ total revenue, net of interest expense (FTE basis)
Total revenue, net of interest expense	(449)	(49)
Net income	(232)	(175)
FTE basis adjustment
Segments’ total revenue, net of interest expense (FTE basis)
Total revenue, net of interest expense	$ (150)	$ (197)