Credit Risk Concentrations (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Concentration Risk [Line Items]
Cash Placed with Banks	$ 351,000	$ 501,500
Credit exposure	1,850,868	1,816,388
On-balance sheet, Loans	837,299	757,336
On-balance sheet, Derivatives	59,677	78,975
Off-balance sheet	940,395	950,997
Consumer
Concentration Risk [Line Items]
Credit exposure	1,050,405	1,010,646
On-balance sheet, Loans	476,284	426,422
On-balance sheet, Derivatives	0	0
Off-balance sheet	573,996	584,116
Consumer, excluding credit card
Concentration Risk [Line Items]
Credit exposure	403,424	353,635
On-balance sheet, Loans	344,821	295,374
On-balance sheet, Derivatives	0	0
Off-balance sheet	58,478	58,153
Credit card
Concentration Risk [Line Items]
Credit exposure	646,981	657,011
On-balance sheet, Loans	131,463	131,048
On-balance sheet, Derivatives	0	0
Off-balance sheet	515,518	525,963
Wholesale
Concentration Risk [Line Items]
Credit exposure	800,463	805,742
On-balance sheet, Loans	361,015	330,914
On-balance sheet, Derivatives	59,677	78,975
Off-balance sheet	366,399	366,881
Wholesale | Subtotal
Concentration Risk [Line Items]
Credit exposure	783,126	770,358
On-balance sheet, Loans	357,050	324,502
On-balance sheet, Derivatives	59,677	78,975
Off-balance sheet	366,399	366,881
Wholesale | Real Estate
Concentration Risk [Line Items]
Credit exposure	116,857	105,975
On-balance sheet, Loans	92,820	79,113
On-balance sheet, Derivatives	312	327
Off-balance sheet	23,725	26,535
Wholesale | Consumer & Retail
Concentration Risk [Line Items]
Credit exposure	85,460	83,663
On-balance sheet, Loans	27,175	25,094
On-balance sheet, Derivatives	1,573	1,845
Off-balance sheet	56,712	56,724
Wholesale | Technology, Media & Telecommunications
Concentration Risk [Line Items]
Credit exposure	57,382	46,655
On-balance sheet, Loans	11,079	11,362
On-balance sheet, Derivatives	1,032	2,190
Off-balance sheet	45,271	33,103
Wholesale | Industrials
Concentration Risk [Line Items]
Credit exposure	54,386	47,859
On-balance sheet, Loans	16,791	16,040
On-balance sheet, Derivatives	1,428	1,303
Off-balance sheet	36,167	30,516
Wholesale | Healthcare
Concentration Risk [Line Items]
Credit exposure	46,053	56,516
On-balance sheet, Loans	16,965	13,794
On-balance sheet, Derivatives	2,751	4,542
Off-balance sheet	26,337	38,180
Wholesale | Banks & Finance Cos
Concentration Risk [Line Items]
Credit exposure	43,398	55,098
On-balance sheet, Loans	20,401	23,367
On-balance sheet, Derivatives	10,218	15,706
Off-balance sheet	12,779	16,025
Wholesale | Oil & Gas
Concentration Risk [Line Items]
Credit exposure	42,077	43,148
On-balance sheet, Loans	13,343	15,616
On-balance sheet, Derivatives	1,902	1,836
Off-balance sheet	26,832	25,696
Wholesale | Utilities
Concentration Risk [Line Items]
Credit exposure	30,853	27,441
On-balance sheet, Loans	5,294	4,844
On-balance sheet, Derivatives	1,689	2,272
Off-balance sheet	23,870	20,325
Wholesale | State & Municipal Govt
Concentration Risk [Line Items]
Credit exposure	29,114	31,068
On-balance sheet, Loans	9,626	7,593
On-balance sheet, Derivatives	3,287	4,002
Off-balance sheet	16,201	19,473
Wholesale | Asset Managers
Concentration Risk [Line Items]
Credit exposure	23,815	27,488
On-balance sheet, Loans	6,703	8,043
On-balance sheet, Derivatives	7,733	9,386
Off-balance sheet	9,379	10,059
Wholesale | Transportation
Concentration Risk [Line Items]
Credit exposure	19,227	20,619
On-balance sheet, Loans	9,157	10,381
On-balance sheet, Derivatives	1,575	2,247
Off-balance sheet	8,495	7,991
Wholesale | Central Govt
Concentration Risk [Line Items]
Credit exposure	17,968	19,881
On-balance sheet, Loans	2,000	1,103
On-balance sheet, Derivatives	13,240	15,527
Off-balance sheet	2,728	3,251
Wholesale | Chemicals & Plastics
Concentration Risk [Line Items]
Credit exposure	15,232	12,612
On-balance sheet, Loans	4,033	3,087
On-balance sheet, Derivatives	369	410
Off-balance sheet	10,830	9,115
Wholesale | Metals & Mining
Concentration Risk [Line Items]
Credit exposure	14,049	14,969
On-balance sheet, Loans	4,622	5,628
On-balance sheet, Derivatives	607	589
Off-balance sheet	8,820	8,752
Wholesale | Automotive
Concentration Risk [Line Items]
Credit exposure	13,864	12,754
On-balance sheet, Loans	4,473	3,779
On-balance sheet, Derivatives	1,350	766
Off-balance sheet	8,041	8,209
Wholesale | Insurance
Concentration Risk [Line Items]
Credit exposure	11,889	13,350
On-balance sheet, Loans	1,094	1,175
On-balance sheet, Derivatives	1,992	3,474
Off-balance sheet	8,803	8,701
Wholesale | Financial Markets Infrastructure
Concentration Risk [Line Items]
Credit exposure	7,973	11,986
On-balance sheet, Loans	724	928
On-balance sheet, Derivatives	2,602	6,789
Off-balance sheet	4,647	4,269
Wholesale | Securities Firms
Concentration Risk [Line Items]
Credit exposure	4,412	4,801
On-balance sheet, Loans	861	1,025
On-balance sheet, Derivatives	1,424	1,351
Off-balance sheet	2,127	2,425
Wholesale | All other
Concentration Risk [Line Items]
Credit exposure	149,117	134,475
On-balance sheet, Loans	109,889	92,530
On-balance sheet, Derivatives	4,593	4,413
Off-balance sheet	34,635	37,532
Wholesale | Loans held-for-sale and loans at fair value
Concentration Risk [Line Items]
Credit exposure	3,965	6,412
On-balance sheet, Loans	3,965	6,412
On-balance sheet, Derivatives	0	0
Off-balance sheet	0	0
Wholesale | Receivables from customers and other
Concentration Risk [Line Items]
Credit exposure	13,372	28,972
On-balance sheet, Loans	0	0
On-balance sheet, Derivatives	0	0
Off-balance sheet	$ 0	$ 0