Derivatives, Derivatives Not Designated as Hedging Instruments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivatives (Textual) [Abstract]
Gains (losses) on derivatives used to hedge residential mortgage servicing rights	$ (176)	$ 513	$ (1,109)	$ 4,448
Net derivative gains (losses) from economic hedges related to mortgage loans held for sale and derivative loan commitments	142	(297)	987	(1,600)
Not designated as hedging instrument [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	486	(1,452)	(752)	2,762
Derivatives (Textual) [Abstract]
Gains (losses) on derivatives used to hedge residential mortgage servicing rights	(176)	513	(1,100)	4,400
Not designated as hedging instrument [Member] | Mortgage banking [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	75	701	(62)	4,413
Not designated as hedging instrument [Member] | Net gains (losses) on trading and securities [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	160	(1,457)	(519)	(1,393)
Not designated as hedging instrument [Member] | Other [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	251	(696)	(171)	(258)
Not designated as hedging instrument [Member] | Personnel expense [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	42	(215)	(357)	(356)
Economic hedges [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	832	(547)	378	2,393
Economic hedges [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(35)	189	(129)	2,757
Economic hedges [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	562	(210)	226	(427)
Economic hedges [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	310	(523)	291	49
Economic hedges [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(5)	(3)	(10)	14
Economic hedges [Member] | Mortgage banking [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(34)	216	(122)	2,829
Economic hedges [Member] | Mortgage banking [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(34)	216	(122)	2,829
Economic hedges [Member] | Mortgage banking [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Economic hedges [Member] | Mortgage banking [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Economic hedges [Member] | Mortgage banking [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Economic hedges [Member] | Net gains (losses) on trading and securities [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	564	(209)	227	(392)
Economic hedges [Member] | Net gains (losses) on trading and securities [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Economic hedges [Member] | Net gains (losses) on trading and securities [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	564	(209)	227	(392)
Economic hedges [Member] | Net gains (losses) on trading and securities [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Economic hedges [Member] | Net gains (losses) on trading and securities [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Economic hedges [Member] | Other [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	302	(554)	273	(44)
Economic hedges [Member] | Other [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(1)	(27)	(7)	(72)
Economic hedges [Member] | Other [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(2)	(1)	(1)	(35)
Economic hedges [Member] | Other [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	310	(523)	291	49
Economic hedges [Member] | Other [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(5)	(3)	(10)	14
Economic hedges [Member] | Personnel expense [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	42	(215)	(357)	(356)
Economic hedges [Member] | Personnel expense [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Economic hedges [Member] | Personnel expense [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	42	(215)	(357)	(356)
Economic hedges [Member] | Personnel expense [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Economic hedges [Member] | Personnel expense [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(346)	(905)	(1,130)	369
Customer accommodation trading and other derivatives [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	298	756	1,579	68
Customer accommodation trading and other derivatives [Member] | Commodity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	31	(356)	75	(468)
Customer accommodation trading and other derivatives [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(773)	(1,433)	(3,251)	896
Customer accommodation trading and other derivatives [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	105	160	545	(242)
Customer accommodation trading and other derivatives [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(7)	(32)	(78)	115
Customer accommodation trading and other derivatives [Member] | Mortgage banking [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	109	485	60	1,584
Customer accommodation trading and other derivatives [Member] | Mortgage banking [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	109	485	60	1,584
Customer accommodation trading and other derivatives [Member] | Mortgage banking [Member] | Commodity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Mortgage banking [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Mortgage banking [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Mortgage banking [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Net gains (losses) on trading and securities [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(404)	(1,248)	(746)	(1,001)
Customer accommodation trading and other derivatives [Member] | Net gains (losses) on trading and securities [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	189	271	1,519	(1,516)
Customer accommodation trading and other derivatives [Member] | Net gains (losses) on trading and securities [Member] | Commodity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	31	(356)	75	(468)
Customer accommodation trading and other derivatives [Member] | Net gains (losses) on trading and securities [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(722)	(1,291)	(2,807)	1,110
Customer accommodation trading and other derivatives [Member] | Net gains (losses) on trading and securities [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	105	160	545	(242)
Customer accommodation trading and other derivatives [Member] | Net gains (losses) on trading and securities [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(7)	(32)	(78)	115
Customer accommodation trading and other derivatives [Member] | Other [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(51)	(142)	(444)	(214)
Customer accommodation trading and other derivatives [Member] | Other [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Other [Member] | Commodity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Other [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	(51)	(142)	(444)	(214)
Customer accommodation trading and other derivatives [Member] | Other [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Other [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Personnel expense [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Personnel expense [Member] | Interest contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Personnel expense [Member] | Commodity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Personnel expense [Member] | Equity contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Personnel expense [Member] | Foreign exchange contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	0	0	0	0
Customer accommodation trading and other derivatives [Member] | Personnel expense [Member] | Credit contracts [Member]
Net Gains Losses Recognized In Income Statement Related To Derivatives Not Designated As Hedging Instruments [Abstract]
Gain (loss) on derivatives not designated as hedging instruments	$ 0	$ 0	$ 0	$ 0