Derivatives, Net Gains (Losses) in Income related to Derivatives Not Designated as Hedging Instruments (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	$ (337)	$ 428	$ 1,482	$ 1,017
Economic Hedges [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	(914)	339	297	791
Economic Hedges [Member] | Interest Rate Contracts, Mortgage Banking [ Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	(383)	475	264	841
Economic Hedges [Member] | Interest Rate Contracts, Other
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	114	(66)	50	(125)
Economic Hedges [Member] | Equity contract [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	25	47	5	123
Economic Hedges [Member] | Foreign exchange contract [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	(670)	(117)	(22)	(48)
Customer Accommodation, Trading, And Other Derivatives [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	577	89	1,185	226
Customer Accommodation, Trading, And Other Derivatives [Member] | Interest Rate Contracts, Mortgage Banking [ Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	(23)	498	364	788
Customer Accommodation, Trading, And Other Derivatives [Member] | Interest Rate Contracts, Other
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	489	(337)	396	(728)
Customer Accommodation, Trading, And Other Derivatives [Member] | Commodity contract [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	13	(13)	44	37
Customer Accommodation, Trading, And Other Derivatives [Member] | Equity contract [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	(139)	(214)	50	(308)
Customer Accommodation, Trading, And Other Derivatives [Member] | Foreign exchange contract [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	215	152	325	414
Customer Accommodation, Trading, And Other Derivatives [Member] | Credit contract [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	7	5	(1)	32
Customer Accommodation, Trading, And Other Derivatives [Member] | Other contract [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Net gains (losses) recognized related to derivatives not designated as hedging instruments	$ 15	$ (2)	$ 7	$ (9)