Fair Value Measurements - Recurring Fair Value (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Assets
Federal funds sold and securities borrowed or purchased under agreements to resell	$ 75,614		$ 98,670
Trading account assets	200,993		227,775
Derivative assets	47,495		53,497
Other Debt Securities Carried at Fair Value	32,844		23,944
Mortgage servicing rights	5,042		5,716		7,378
Loans Held-for-sale, Fair Value Disclosure	6,656		11,659
Other assets	18,055		26,490
Liabilities
Federal funds purchased and securities loaned or sold under agreements to repurchase	33,684		42,639
Derivative liabilities	37,407		46,016
Long-term debt	47,035		49,161
Assets and Liabilities, Recurring Basis, Supplemental Information:
Fair value assets, level 1 to level 2	500		2,000
Fair value liabilities, level 1 to level 2			350
Fair value assets, level 2 to level 1			785
Fair value liabilities, level 2 to level 1			40
US Government-sponsored Enterprises Debt Securities [Member]
Assets
Trading account assets	17,200		30,600
US Government Corporations and Agencies Securities [Member]
Assets
Other Debt Securities Carried at Fair Value	4,062		491
Private Equity Investment [Member]
Assets and Liabilities, Recurring Basis, Supplemental Information:
Fair value assets, level 1 to level 2			940
Fair value assets, level 2 to level 1			535
Recurring [Member]
Assets
Federal funds sold and securities borrowed or purchased under agreements to resell	75,614		98,670
Trading account assets	200,993		227,775
Derivative assets	47,495	[1],[2]	53,497	[2]
Total available-for-sale debt securities	235,951		286,906
Other Debt Securities Carried at Fair Value	32,844		23,944
Loans and Leases	10,042		9,002
Mortgage servicing rights	5,042		5,716
Loans Held-for-sale, Fair Value Disclosure	6,656		11,659
Other assets	18,055		26,490
Assets, Fair Value Disclosure	632,692		743,659
Liabilities
Interest-bearing deposits in U.S. offices	1,899		2,262
Federal funds purchased and securities loaned or sold under agreements to repurchase	33,684		42,639
Total trading account liabilities	83,469		73,587
Derivative liabilities	37,407	[1],[2]	46,016	[2]
Short-term borrowings fair value disclosure	1,520		4,074
Accrued expenses and other liabilities	11,233		16,594
Long-term debt	47,035		49,161
Total liabilities	216,247		234,333
Recurring [Member] | US Government Corporations and Agencies Securities [Member]
Liabilities
Total trading account liabilities	27,263		23,430
Recurring [Member] | Equity Securities [Member]
Liabilities
Total trading account liabilities	27,585		22,492
Recurring [Member] | Non-U.S. sovereign debt [Member]
Liabilities
Total trading account liabilities	22,142		20,244
Recurring [Member] | Corporate securities, trading loans and other [Member]
Liabilities
Total trading account liabilities	6,479		7,421
Recurring [Member] | US government and agency securities
Assets
Trading account assets	48,847	[1]	86,974
Recurring [Member] | Corporate securities, trading loans and other [Member]
Assets
Trading account assets	32,452		37,900
Recurring [Member] | Equity Securities [Member]
Assets
Trading account assets	64,451		43,315
Recurring [Member] | Non-U.S. sovereign debt [Member]
Assets
Trading account assets	37,224		42,746
Recurring [Member] | Mortgage trading loans and ABS [Member]
Assets
Trading account assets	18,019		16,840
Recurring [Member] | U.S. Treasury securities and agency securities [Member]
Assets
Total available-for-sale debt securities	8,954		24,472
Other Debt Securities Carried at Fair Value	4,062		491
Recurring [Member] | Agency [Member]
Assets
Total available-for-sale debt securities	164,935		188,149
Other Debt Securities Carried at Fair Value	16,500		13,073
Recurring [Member] | Agency-collateralized mortgage obligations [Member]
Assets
Total available-for-sale debt securities	22,492		37,538
Other Debt Securities Carried at Fair Value	218		929
Recurring [Member] | Non-agency residential [Member]
Assets
Total available-for-sale debt securities	6,239		9,494
Recurring [Member] | Non-agency commercial [Member]
Assets
Total available-for-sale debt securities	2,480		3,924
Other Debt Securities Carried at Fair Value	749
Recurring [Member] | Non-U.S. Securities [Member]
Assets
Total available-for-sale debt securities	7,220		5,618
Other Debt Securities Carried at Fair Value	11,315		9,451
Recurring [Member] | Corporate/Agency bonds [Member]
Assets
Total available-for-sale debt securities	873		1,450
Recurring [Member] | Other taxable securities [Member]
Assets
Total available-for-sale debt securities	16,830		12,128
Recurring [Member] | Tax-exempt securities [Member]
Assets
Total available-for-sale debt securities	5,928		4,133
Recurring [Member] | Level 1 [Member]
Assets
Federal funds sold and securities borrowed or purchased under agreements to resell		[3]		[4]
Trading account assets	101,050	[3]	116,345	[4]
Derivative assets	2,374	[2],[3]	2,997	[2],[4]
Total available-for-sale debt securities	10,309	[3]	24,171	[4]
Other Debt Securities Carried at Fair Value	11,519	[3]	9,642	[4]
Loans and Leases		[3]		[4]
Mortgage servicing rights		[3]		[4]
Loans Held-for-sale, Fair Value Disclosure		[3]		[4]
Other assets	14,474	[3]	18,535	[4]
Assets, Fair Value Disclosure	139,726	[3]	171,690	[4]
Liabilities
Interest-bearing deposits in U.S. offices		[3]		[4]
Federal funds purchased and securities loaned or sold under agreements to repurchase		[3]		[4]
Total trading account liabilities	72,062	[3]	61,565	[4]
Derivative liabilities	1,968	[2],[3]	2,859	[2],[4]
Short-term borrowings fair value disclosure		[3]		[4]
Accrued expenses and other liabilities	10,130	[3]	15,457	[4]
Long-term debt		[3]		[4]
Total liabilities	84,160	[3]	79,881	[4]
Recurring [Member] | Level 1 [Member] | US Government Corporations and Agencies Securities [Member]
Liabilities
Total trading account liabilities	26,915	[3]	22,351	[4]
Recurring [Member] | Level 1 [Member] | Equity Securities [Member]
Liabilities
Total trading account liabilities	23,874	[3]	19,852	[4]
Recurring [Member] | Level 1 [Member] | Non-U.S. sovereign debt [Member]
Liabilities
Total trading account liabilities	20,755	[3]	18,875	[4]
Recurring [Member] | Level 1 [Member] | Corporate securities, trading loans and other [Member]
Liabilities
Total trading account liabilities	518	[3]	487	[4]
Recurring [Member] | Level 1 [Member] | US government and agency securities
Assets
Trading account assets	34,222	[1],[3]	57,655	[4]
Recurring [Member] | Level 1 [Member] | Corporate securities, trading loans and other [Member]
Assets
Trading account assets	1,147	[3]	1,292	[4]
Recurring [Member] | Level 1 [Member] | Equity Securities [Member]
Assets
Trading account assets	41,324	[3]	28,144	[4]
Recurring [Member] | Level 1 [Member] | Non-U.S. sovereign debt [Member]
Assets
Trading account assets	24,357	[3]	29,254	[4]
Recurring [Member] | Level 1 [Member] | Mortgage trading loans and ABS [Member]
Assets
Trading account assets		[3]		[4]
Recurring [Member] | Level 1 [Member] | U.S. Treasury securities and agency securities [Member]
Assets
Total available-for-sale debt securities	6,591	[3]	21,514	[4]
Other Debt Securities Carried at Fair Value	4,062	[3]	491	[4]
Recurring [Member] | Level 1 [Member] | Agency [Member]
Assets
Total available-for-sale debt securities		[3]		[4]
Other Debt Securities Carried at Fair Value		[3]		[4]
Recurring [Member] | Level 1 [Member] | Agency-collateralized mortgage obligations [Member]
Assets
Total available-for-sale debt securities		[3]		[4]
Other Debt Securities Carried at Fair Value		[3]		[4]
Recurring [Member] | Level 1 [Member] | Non-agency residential [Member]
Assets
Total available-for-sale debt securities		[3]		[4]
Recurring [Member] | Level 1 [Member] | Non-agency commercial [Member]
Assets
Total available-for-sale debt securities		[3]		[4]
Other Debt Securities Carried at Fair Value		[3]
Recurring [Member] | Level 1 [Member] | Non-U.S. Securities [Member]
Assets
Total available-for-sale debt securities	3,698	[3]	2,637	[4]
Other Debt Securities Carried at Fair Value	7,457	[3]	9,151	[4]
Recurring [Member] | Level 1 [Member] | Corporate/Agency bonds [Member]
Assets
Total available-for-sale debt securities		[3]		[4]
Recurring [Member] | Level 1 [Member] | Other taxable securities [Member]
Assets
Total available-for-sale debt securities	20	[3]	20	[4]
Recurring [Member] | Level 1 [Member] | Tax-exempt securities [Member]
Assets
Total available-for-sale debt securities		[3]		[4]
Recurring [Member] | Level 2 [Member]
Assets
Federal funds sold and securities borrowed or purchased under agreements to resell	75,614	[3]	98,670	[4]
Trading account assets	90,899	[3]	101,871	[4]
Derivative assets	910,602	[2],[3]	1,372,398	[2],[4]
Total available-for-sale debt securities	220,882	[3]	257,644	[4]
Other Debt Securities Carried at Fair Value	21,325	[3]	14,302	[4]
Loans and Leases	6,985	[3]	6,715	[4]
Mortgage servicing rights		[3]		[4]
Loans Held-for-sale, Fair Value Disclosure	5,727	[3]	8,926	[4]
Other assets	1,912	[3]	4,826	[4]
Assets, Fair Value Disclosure	1,333,946	[3]	1,865,352	[4]
Liabilities
Interest-bearing deposits in U.S. offices	1,899	[3]	2,262	[4]
Federal funds purchased and securities loaned or sold under agreements to repurchase	33,684	[3]	42,639	[4]
Total trading account liabilities	11,372	[3]	11,958	[4]
Derivative liabilities	897,107	[2],[3]	1,355,309	[2],[4]
Short-term borrowings fair value disclosure	1,520	[3]	4,074	[4]
Accrued expenses and other liabilities	1,093	[3]	1,122	[4]
Long-term debt	45,045	[3]	46,860	[4]
Total liabilities	991,720	[3]	1,464,224	[4]
Recurring [Member] | Level 2 [Member] | US Government Corporations and Agencies Securities [Member]
Liabilities
Total trading account liabilities	348	[3]	1,079	[4]
Recurring [Member] | Level 2 [Member] | Equity Securities [Member]
Liabilities
Total trading account liabilities	3,711	[3]	2,640	[4]
Recurring [Member] | Level 2 [Member] | Non-U.S. sovereign debt [Member]
Liabilities
Total trading account liabilities	1,387	[3]	1,369	[4]
Recurring [Member] | Level 2 [Member] | Corporate securities, trading loans and other [Member]
Liabilities
Total trading account liabilities	5,926	[3]	6,870	[4]
Recurring [Member] | Level 2 [Member] | US government and agency securities
Assets
Trading account assets	14,625	[1],[3]	29,319	[4]
Recurring [Member] | Level 2 [Member] | Corporate securities, trading loans and other [Member]
Assets
Trading account assets	27,746	[3]	32,882	[4]
Recurring [Member] | Level 2 [Member] | Equity Securities [Member]
Assets
Trading account assets	22,741	[3]	14,626	[4]
Recurring [Member] | Level 2 [Member] | Non-U.S. sovereign debt [Member]
Assets
Trading account assets	12,399	[3]	13,139	[4]
Recurring [Member] | Level 2 [Member] | Mortgage trading loans and ABS [Member]
Assets
Trading account assets	13,388	[3]	11,905	[4]
Recurring [Member] | Level 2 [Member] | U.S. Treasury securities and agency securities [Member]
Assets
Total available-for-sale debt securities	2,363	[3]	2,958	[4]
Other Debt Securities Carried at Fair Value		[3]		[4]
Recurring [Member] | Level 2 [Member] | Agency [Member]
Assets
Total available-for-sale debt securities	164,935	[3]	188,149	[4]
Other Debt Securities Carried at Fair Value	16,500	[3]	13,073	[4]
Recurring [Member] | Level 2 [Member] | Agency-collateralized mortgage obligations [Member]
Assets
Total available-for-sale debt securities	22,492	[3]	37,538	[4]
Other Debt Securities Carried at Fair Value	218	[3]	929	[4]
Recurring [Member] | Level 2 [Member] | Non-agency residential [Member]
Assets
Total available-for-sale debt securities	6,239	[3]	9,494	[4]
Recurring [Member] | Level 2 [Member] | Non-agency commercial [Member]
Assets
Total available-for-sale debt securities	2,480	[3]	3,914	[4]
Other Debt Securities Carried at Fair Value	749	[3]
Recurring [Member] | Level 2 [Member] | Non-U.S. Securities [Member]
Assets
Total available-for-sale debt securities	3,415	[3]	2,981	[4]
Other Debt Securities Carried at Fair Value	3,858	[3]	300	[4]
Recurring [Member] | Level 2 [Member] | Corporate/Agency bonds [Member]
Assets
Total available-for-sale debt securities	873	[3]	1,358	[4]
Recurring [Member] | Level 2 [Member] | Other taxable securities [Member]
Assets
Total available-for-sale debt securities	12,963	[3]	8,180	[4]
Recurring [Member] | Level 2 [Member] | Tax-exempt securities [Member]
Assets
Total available-for-sale debt securities	5,122	[3]	3,072	[4]
Recurring [Member] | Level 3 [Member]
Assets
Federal funds sold and securities borrowed or purchased under agreements to resell
Trading account assets	9,044		9,559
Derivative assets	7,277	[2]	8,073	[2]	14,400
Total available-for-sale debt securities	4,760		5,091
Other Debt Securities Carried at Fair Value
Loans and Leases	3,057		2,287
Mortgage servicing rights	5,042		5,716
Loans Held-for-sale, Fair Value Disclosure	929		2,733
Other assets	1,669		3,129
Assets, Fair Value Disclosure	31,778		36,588
Liabilities
Interest-bearing deposits in U.S. offices
Federal funds purchased and securities loaned or sold under agreements to repurchase
Total trading account liabilities	35		64
Derivative liabilities	7,301	[2]	6,605	[2]	8,500
Short-term borrowings fair value disclosure
Accrued expenses and other liabilities	10		15
Long-term debt	1,990		2,301
Total liabilities	9,336		8,985
Recurring [Member] | Level 3 [Member] | US Government Corporations and Agencies Securities [Member]
Liabilities
Total trading account liabilities
Recurring [Member] | Level 3 [Member] | Equity Securities [Member]
Liabilities
Total trading account liabilities
Recurring [Member] | Level 3 [Member] | Non-U.S. sovereign debt [Member]
Liabilities
Total trading account liabilities
Recurring [Member] | Level 3 [Member] | Corporate securities, trading loans and other [Member]
Liabilities
Total trading account liabilities	35		64
Recurring [Member] | Level 3 [Member] | US government and agency securities
Assets
Trading account assets		[1]
Recurring [Member] | Level 3 [Member] | Corporate securities, trading loans and other [Member]
Assets
Trading account assets	3,559		3,726
Recurring [Member] | Level 3 [Member] | Equity Securities [Member]
Assets
Trading account assets	386		545
Recurring [Member] | Level 3 [Member] | Non-U.S. sovereign debt [Member]
Assets
Trading account assets	468		353
Recurring [Member] | Level 3 [Member] | Mortgage trading loans and ABS [Member]
Assets
Trading account assets	4,631		4,935
Recurring [Member] | Level 3 [Member] | U.S. Treasury securities and agency securities [Member]
Assets
Total available-for-sale debt securities
Other Debt Securities Carried at Fair Value
Recurring [Member] | Level 3 [Member] | Agency [Member]
Assets
Total available-for-sale debt securities
Other Debt Securities Carried at Fair Value
Recurring [Member] | Level 3 [Member] | Agency-collateralized mortgage obligations [Member]
Assets
Total available-for-sale debt securities
Other Debt Securities Carried at Fair Value
Recurring [Member] | Level 3 [Member] | Non-agency residential [Member]
Assets
Total available-for-sale debt securities
Recurring [Member] | Level 3 [Member] | Non-agency commercial [Member]
Assets
Total available-for-sale debt securities			10
Other Debt Securities Carried at Fair Value
Recurring [Member] | Level 3 [Member] | Non-U.S. Securities [Member]
Assets
Total available-for-sale debt securities	107
Other Debt Securities Carried at Fair Value
Recurring [Member] | Level 3 [Member] | Corporate/Agency bonds [Member]
Assets
Total available-for-sale debt securities			92
Recurring [Member] | Level 3 [Member] | Other taxable securities [Member]
Assets
Total available-for-sale debt securities	3,847		3,928
Recurring [Member] | Level 3 [Member] | Tax-exempt securities [Member]
Assets
Total available-for-sale debt securities	806		1,061
Recurring [Member] | Netting Adjustments [Member]
Assets
Federal funds sold and securities borrowed or purchased under agreements to resell		[5]		[5]
Trading account assets		[5]		[5]
Derivative assets	(872,758)	[2],[5]	(1,329,971)	[2],[5]
Total available-for-sale debt securities		[5]		[5]
Other Debt Securities Carried at Fair Value		[5]		[5]
Loans and Leases		[5]		[5]
Mortgage servicing rights		[5]		[5]
Loans Held-for-sale, Fair Value Disclosure		[5]		[5]
Other assets		[5]		[5]
Assets, Fair Value Disclosure	(872,758)	[5]	(1,329,971)	[5]
Liabilities
Interest-bearing deposits in U.S. offices		[5]		[5]
Federal funds purchased and securities loaned or sold under agreements to repurchase		[5]		[5]
Total trading account liabilities		[5]		[5]
Derivative liabilities	(868,969)	[2],[5]	(1,318,757)	[2],[5]
Short-term borrowings fair value disclosure		[5]		[5]
Accrued expenses and other liabilities		[5]		[5]
Long-term debt		[5]		[5]
Total liabilities	(868,969)	[5]	(1,318,757)	[5]
Recurring [Member] | Netting Adjustments [Member] | US Government Corporations and Agencies Securities [Member]
Liabilities
Total trading account liabilities		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Equity Securities [Member]
Liabilities
Total trading account liabilities		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Non-U.S. sovereign debt [Member]
Liabilities
Total trading account liabilities		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Corporate securities, trading loans and other [Member]
Liabilities
Total trading account liabilities		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | US government and agency securities
Assets
Trading account assets		[1],[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Corporate securities, trading loans and other [Member]
Assets
Trading account assets		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Equity Securities [Member]
Assets
Trading account assets		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Non-U.S. sovereign debt [Member]
Assets
Trading account assets		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Mortgage trading loans and ABS [Member]
Assets
Trading account assets		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | U.S. Treasury securities and agency securities [Member]
Assets
Total available-for-sale debt securities		[5]		[5]
Other Debt Securities Carried at Fair Value		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Agency [Member]
Assets
Total available-for-sale debt securities		[5]		[5]
Other Debt Securities Carried at Fair Value		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Agency-collateralized mortgage obligations [Member]
Assets
Total available-for-sale debt securities		[5]
Other Debt Securities Carried at Fair Value		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Non-agency residential [Member]
Assets
Total available-for-sale debt securities		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Non-agency commercial [Member]
Assets
Total available-for-sale debt securities		[5]		[5]
Other Debt Securities Carried at Fair Value		[5]
Recurring [Member] | Netting Adjustments [Member] | Non-U.S. Securities [Member]
Assets
Total available-for-sale debt securities		[5]		[5]
Other Debt Securities Carried at Fair Value		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Corporate/Agency bonds [Member]
Assets
Total available-for-sale debt securities		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Other taxable securities [Member]
Assets
Total available-for-sale debt securities		[5]		[5]
Recurring [Member] | Netting Adjustments [Member] | Tax-exempt securities [Member]
Assets
Total available-for-sale debt securities		[5]		[5]

[1] Includes $17.2 billion of government-sponsored enterprise obligations.

[2] For further disaggregation of derivative assets and liabilities, see Note 2 – Derivatives.

[3] During 2013, $500 million of other assets were transferred from Level 1 to Level 2 primarily due to a restriction that became effective for a private equity investment that was subsequently sold once the restriction was lifted.

[4] During 2012, $2.0 billion and $350 million of assets and liabilities were transferred from Level 1 to Level 2, and $785 million and $40 million of assets and liabilities were transferred from Level 2 to Level 1. Of the asset transfers from Level 1 to Level 2, $940 million was due to a restriction that became effective for a private equity investment during 2012, while $535 million of the transfers from Level 2 to Level 1 was due to the lapse of this restriction during 2012. The remaining transfers were the result of additional information associated with certain equities, derivative contracts and private equity investments.

[5] Amounts represent the impact of legally enforceable master netting agreements and also cash collateral held or placed with the same counterparties.