Off-Balance Sheet Lending-Related Financial Instruments, Guarantees and Other Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	$ 940,395	$ 950,997	$ 929,678
Off-balance sheet lending-related financial commitments, carrying value	1,213	1,176
Allowance for lending-related commitments	148	275
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information [Abstract]
Standby letters of credit, unissued commitments		45,600
Unfunded commitments investments private equity funds third party	50	147
Unfunded commitments investments other equity investments	871	961
Investments entities that calculate net asset value per share, unfunded commitments	73	150
Commitments to noninvestment-grade counterparties in connection with leveraged finance activities	32,100	23,400
Maximum
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information [Abstract]
Secured clearance advance facility outstanding commitment	2,900	12,600
Wholesale
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	366,399	366,881	$ 344,238
Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	657,941
Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	114,549
Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	148,081
Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	19,824
Total consumer
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	573,996	584,116
Off-balance sheet lending-related financial commitments, carrying value	14	13
Total consumer | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	552,427
Total consumer | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	10,033
Total consumer | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	1,555
Total consumer | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	9,981
Total consumer, excluding credit card
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	58,478	58,153
Off-balance sheet lending-related financial commitments, carrying value	14	13
Total consumer, excluding credit card | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	36,909
Total consumer, excluding credit card | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	10,033
Total consumer, excluding credit card | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	1,555
Total consumer, excluding credit card | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	9,981
Home equity | Senior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	10,832	11,807
Off-balance sheet lending-related financial commitments, carrying value	0	0
Home equity | Junior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	11,924	14,859
Off-balance sheet lending-related financial commitments, carrying value	0	0
Home equity | Expires in 1 year or less | Senior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	1,546
Home equity | Expires in 1 year or less | Junior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	2,375
Home equity | Expires after 1 year through 3 years | Senior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	3,817
Home equity | Expires after 1 year through 3 years | Junior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	4,354
Home equity | Expires after 3 years through 5 years | Senior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	726
Home equity | Expires after 3 years through 5 years | Junior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	657
Home equity | Expires after 5 years | Senior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	4,743
Home equity | Expires after 5 years | Junior lien
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	4,538
Mortgage | Warranty Reserves
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Allowance for lending-related commitments	148	275
Mortgage | Prime mortgage
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	12,992	8,579
Off-balance sheet lending-related financial commitments, carrying value	0	0
Mortgage | Subprime
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0	0
Off-balance sheet lending-related financial commitments, carrying value	0	0
Mortgage | Expires in 1 year or less | Prime mortgage
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	12,992
Mortgage | Expires in 1 year or less | Subprime
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Mortgage | Expires after 1 year through 3 years | Prime mortgage
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Mortgage | Expires after 1 year through 3 years | Subprime
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Mortgage | Expires after 3 years through 5 years | Prime mortgage
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Mortgage | Expires after 3 years through 5 years | Subprime
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Mortgage | Expires after 5 years | Prime mortgage
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Mortgage | Expires after 5 years | Subprime
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Auto
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	10,237	10,462
Off-balance sheet lending-related financial commitments, carrying value	2	2
Auto | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	8,907
Auto | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	1,160
Auto | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	80
Auto | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	90
Business banking
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	12,351	11,894
Off-balance sheet lending-related financial commitments, carrying value	12	11
Business banking | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	11,085
Business banking | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	699
Business banking | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	92
Business banking | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	475
Student and other
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	142	552
Off-balance sheet lending-related financial commitments, carrying value	0	0
Student and other | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	4
Student and other | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	3
Student and other | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Student and other | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	135
Credit card
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	515,518	525,963
Off-balance sheet lending-related financial commitments, carrying value	0	0
Credit card | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	515,518
Credit card | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Credit card | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Credit card | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Total wholesale
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	366,399	366,881
Off-balance sheet lending-related financial commitments, carrying value	$ 1,199	$ 1,163
Total wholesale | Wholesale | Total U.S.
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information [Abstract]
Off balance sheet lending related financial commitments	77.00%	73.00%
Total wholesale | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	$ 105,514
Total wholesale | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	104,516
Total wholesale | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	146,526
Total wholesale | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	9,843
Other unfunded commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	323,325	$ 318,278
Off-balance sheet lending-related financial commitments, carrying value	649	491
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information [Abstract]
Risk participations for other unfunded commitments to extend credit	385	243
Credit enhancements and bond and commercial paper liquidity commitments to US states and municipalities hospitals and other not for profit entities	12,300	14,800
Other unfunded commitments to extend credit | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	85,861
Other unfunded commitments to extend credit | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	89,925
Other unfunded commitments to extend credit | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	140,640
Other unfunded commitments to extend credit | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	6,899
Standby letters of credit and other financial guarantees
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	39,133	44,272
Off-balance sheet lending-related financial commitments, carrying value	548	671
Allowance for lending-related commitments	121	117
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information [Abstract]
Risk participations for standby letters of credit and other financial guarantees	11,200	13,000
Credit enhancements and bond and commercial paper liquidity commitments to US states and municipalities hospitals and other not for profit entities	9,600	13,300
Standby letters of credit and other financial guarantees | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	16,083
Standby letters of credit and other financial guarantees | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	14,287
Standby letters of credit and other financial guarantees | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	5,819
Standby letters of credit and other financial guarantees | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	2,944
Other letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	3,941	4,331
Off-balance sheet lending-related financial commitments, carrying value	2	1
Allowance for lending-related commitments	2	1
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information [Abstract]
Risk participations for other letters of credit	341	469
Other letters of credit | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	3,570
Other letters of credit | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	304
Other letters of credit | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	67
Other letters of credit | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet lending-related financial commitments, contractual amount	0
Securities lending indemnification agreements and guarantees
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	183,329	171,059
Guarantor obligations, current carrying value	0	0
Off balance sheet lending related financial instruments guarantees and other commitments - supplemental information [Abstract]
Indemnification agreement securities lending guarantees collateral held in support of	190,600	177,100
Securities lending indemnification agreements and guarantees | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	183,329
Securities lending indemnification agreements and guarantees | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	0
Securities lending indemnification agreements and guarantees | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	0
Securities lending indemnification agreements and guarantees | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	0
Derivatives qualifying as guarantees
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	53,784	53,589
Guarantor obligations, current carrying value	222	80
Derivatives qualifying as guarantees | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	3,194
Derivatives qualifying as guarantees | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	285
Derivatives qualifying as guarantees | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	11,160
Derivatives qualifying as guarantees | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	39,145
Unsettled reverse repurchase and securities borrowing agreements
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	42,482	40,993
Guarantor obligations, current carrying value	0	0
Unsettled reverse repurchase and securities borrowing agreements | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	42,482
Unsettled reverse repurchase and securities borrowing agreements | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	0
Unsettled reverse repurchase and securities borrowing agreements | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	0
Unsettled reverse repurchase and securities borrowing agreements | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	0
Unsettled repurchase and securities lending agreements [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	21,798	42,578
Guarantor obligations, current carrying value	0	0
Unsettled repurchase and securities lending agreements [Member] | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	21,798
Unsettled repurchase and securities lending agreements [Member] | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	0
Unsettled repurchase and securities lending agreements [Member] | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	0
Unsettled repurchase and securities lending agreements [Member] | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	0
Loans sold with recourse
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan sale and securitization-related indemnifications, Contractual amount	4,274	6,063
Loan sale and securitization-related indemnifications, Carrying value	82	102
Other guarantees and commitments
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	5,580	5,720
Guarantor obligations, current carrying value	(94)	(121)
Other guarantees and commitments | Expires in 1 year or less
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	369
Other guarantees and commitments | Expires after 1 year through 3 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	2,603
Other guarantees and commitments | Expires after 3 years through 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	1,075
Other guarantees and commitments | Expires after 5 years
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	1,533
Letters of credit hedged by derivative transactions
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Other guarantees and commitments, contractual amount	$ 4,600	$ 4,500
Days Past Due, 60 or More | Credit card
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Line of credit close criteria, period past due	60 days