State Street (STT) 10-Q 6 Nov 13 2013 Q3 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document And Entity Information [Abstract]	'	'
Entity Registrant Name	'STATE STREET Corp	'
Entity Central Index Key	'0000093751	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	439,001,221

Consolidated_Statement_of_Inco

Consolidated Statement of Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fee revenue:	'	'	'	'
Servicing fees	$1,211	$1,100	$3,587	$3,264
Management fees	276	251	816	733
Trading services	256	232	833	767
Securities finance	74	91	283	331
Processing fees and other	66	45	192	187
Total fee revenue	1,883	1,719	5,711	5,282
Net interest revenue:	'	'	'	'
Interest revenue	643	730	2,030	2,281
Interest expense	97	111	312	365
Net interest revenue	546	619	1,718	1,916
Gains (losses) related to investment securities, net:	'	'	'	'
Net gains (losses) from sales of available-for-sale securities	6	24	11	29
Losses from other-than-temporary impairment	-8	-4	-8	-50
Losses reclassified (from) to other comprehensive income	-2	-2	-12	23
Gains (losses) related to investment securities, net	-4	18	-9	2
Total revenue	2,425	2,356	7,420	7,200
Provision for loan losses	0	0	0	-1
Expenses:	'	'	'	'
Compensation and employee benefits	903	916	2,855	2,922
Information systems and communications	235	211	707	610
Transaction processing services	185	170	551	523
Occupancy	113	115	343	349
Claims resolution	0	-362	0	-362
Acquisition and restructuring costs	30	28	74	86
Professional services	98	89	280	266
Amortization of other intangible assets	53	46	160	145
Other	105	202	376	483
Total expenses	1,722	1,415	5,346	5,022
Income before income tax expense	703	941	2,074	2,179
Income tax expense	163	267	491	588
Net income	540	674	1,583	1,591
Net income available to common shareholders	$531	$654	$1,557	$1,551
Earnings per common share:	'	'	'	'
Basic (per share)	$1.20	$1.39	$3.46	$3.23
Diluted (per share)	$1.17	$1.36	$3.40	$3.19
Average common shares outstanding (in thousands):	'	'	'	'
Basic (in shares)	442,860	472,355	449,742	479,536
Diluted (in shares)	452,154	480,010	458,392	485,813
Cash dividends declared (in dollars per share)	$0.26	$0.24	$0.78	$0.72

Consolidated_Statement_of_Comp

Consolidated Statement of Comprehensive Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Other Comprehensive Income [Abstract]	'	'	'	'
Net income	$540	$674	$1,583	$1,591
Other comprehensive income (loss), net of related taxes:	'	'	'	'
Foreign currency translation, net of related taxes	326	172	23	19
Change in net unrealized losses on available-for-sale securities, net of reclassification adjustment and net of related taxes	111	543	-642	794
Change in net unrealized losses on available-for-sale securities designated in fair value hedges, net of related taxes	1	-1	61	14
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes	3	7	14	10
Change in net unrealized losses on cash flow hedges, net of related taxes	-33	-5	61	-1
Change in unrealized losses on retirement plans, net of related taxes	1	7	9	9
Other comprehensive income (loss)	409	723	-474	845
Total comprehensive income	$949	$1,397	$1,109	$2,436

Consolidated_Statement_of_Comp1

Consolidated Statement of Comprehensive Income (Unaudited) (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Other Comprehensive Income [Abstract]	'	'	'	'
Foreign currency translation, net of related taxes of	$66	$26	($27)	$60
Change in net unrealized losses on available-for-sale securities, net of reclassification adjustment and net of related taxes of	76	326	-402	471
Change in net unrealized losses on available-for-sale securities designated in fair value hedges, net of related taxes of	0	-1	40	9
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes of	1	4	8	6
Change in net unrealized losses on cash flow hedges, net of related taxes of	-21	3	38	4
Change in minimum pension liability, net of related taxes of	$6	($7)	$12	($6)

Consolidated_Statement_of_Cond

Consolidated Statement of Condition (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Assets:	'	'
Cash and due from banks	$3,896	$2,590
Interest-bearing deposits with banks	38,636	50,763
Securities purchased under resale agreements	5,827	5,016
Trading account assets	916	637
Investment securities available for sale	99,982	109,682
Investment securities held to maturity (fair value of $16,543 and $11,661)	16,698	11,379
Loans and leases (less allowance for losses of $22 and $22)	15,556	12,285
Premises and equipment (net of accumulated depreciation of $4,319 and $4,037)	1,816	1,728
Accrued income receivable	2,094	1,970
Goodwill	6,006	5,977
Other intangible assets	2,396	2,539
Other assets	23,357	18,016
Total assets	217,180	222,582
Deposits:	'	'
Noninterest-bearing	45,679	44,445
Interest-bearing—U.S.	6,575	19,201
Interest-bearing—non-U.S.	101,945	100,535
Total deposits	154,199	164,181
Securities sold under repurchase agreements	10,123	8,006
Federal funds purchased	94	399
Other short-term borrowings	3,657	4,502
Accrued expenses and other liabilities	19,929	17,196
Long-term debt	8,748	7,429
Total liabilities	196,750	201,713
Commitments, guarantees and contingencies (note 8)	'	'
Shareholders’ equity:	'	'
Common stock, $1 par: 750,000,000 shares authorized; 503,885,462 and 503,900,268 shares issued	504	504
Surplus	9,753	9,667
Retained earnings	12,963	11,751
Accumulated other comprehensive income (loss)	-114	360
Treasury stock, at cost (62,587,206 and 45,238,208 shares)	-3,166	-1,902
Total shareholders’ equity	20,430	20,869
Total liabilities and shareholders’ equity	217,180	222,582
Series C Preferred Stock	'	'
Shareholders’ equity:	'	'
Preferred stock, no par: 3,500,000 shares authorized; 5,000 shares issued and outstanding	$490	$489

Consolidated_Statement_of_Cond1

Consolidated Statement of Condition (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, except Share data, unless otherwise specified
Current Assets:	'	'
Investment securities held to maturity, fair value	$16,543	$11,661
Loans and leases, allowance for losses	22	22
Premises and equipment, accumulated depreciation	$4,319	$4,037
Stockholders' Equity:	'	'
Common stock, par value (in dollars per share)	$1	$1
Common stock, shares authorized (in shares)	750,000,000	750,000,000
Common stock, shares issued (in shares)	503,885,462	503,900,268
Preferred stock, shares authorized (in shares)	3,500,000	3,500,000
Treasury stock, shares (in shares)	62,587,206	45,238,208
Series C Preferred Stock	'	'
Stockholders' Equity:	'	'
Preferred stock, shares issued, Series C (in shares)	5,000	5,000
Preferred stock, shares outstanding, Series C (in shares)	5,000	5,000

Consolidated_Statement_of_Chan

Consolidated Statement of Changes In Shareholders' Equity (Unaudited) (USD $)	Total	PREFERRED STOCK	COMMON STOCK	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	TREASURY STOCK
In Millions, except Share data, unless otherwise specified
Beginning balance at Dec. 31, 2011	$19,398	$500	$504	$9,557	$10,176	($659)	($680)
Beginning balance (shares) at Dec. 31, 2011	'	'	503,966,000	'	'	'	16,542,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net income	1,591	'	'	'	1,591	'	'
Other comprehensive income	845	'	'	'	'	845	'
Commitment to redeem preferred stock	-500	-500	'	'	'	'	'
Preferred stock issued	488	488	'	'	'	'	'
Cash dividends declared:	'	'	'	'	'	'	'
Common stock	-346	'	'	'	-346	'	'
Preferred stock	-29	'	'	'	-29	'	'
Common stock acquired (shares)	'	'	'	'	'	'	22,496,000
Common stock acquired	-960	'	'	'	'	'	-960
Common stock awards and options exercised, including related taxes (shares)	'	'	-48,000	'	'	'	-3,938,000
Common stock awards and options exercised, including related taxes	260	'	'	75	'	'	185
Other	2	'	'	2	'	'	'
Other (shares)	'	'	'	'	'	'	-9,000
Ending balance at Sep. 30, 2012	20,749	488	504	9,634	11,392	186	-1,455
Ending balance (shares) at Sep. 30, 2012	'	'	503,918,000	'	'	'	35,091,000
Beginning balance at Jun. 30, 2012	'	'	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net income	674	'	'	'	'	'	'
Cash dividends declared:	'	'	'	'	'	'	'
Common stock	'	'	'	'	-113	'	'
Ending balance at Sep. 30, 2012	20,749	'	'	'	11,392	'	'
Beginning balance at Dec. 31, 2012	20,869	489	504	9,667	11,751	360	-1,902
Beginning balance (shares) at Dec. 31, 2012	'	'	503,900,000	'	'	'	45,238,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net income	1,583	'	'	'	1,583	'	'
Other comprehensive income	-474	'	'	'	'	-474	'
Accretion of issuance costs	0	1	'	'	-1	'	'
Cash dividends declared:	'	'	'	'	'	'	'
Common stock	-350	'	'	'	-350	'	'
Preferred stock	-20	'	'	'	-20	'	'
Common stock acquired (shares)	23,200,000	'	'	'	'	'	23,235,000
Common stock acquired	-1,480	'	'	'	'	'	-1,480
Common stock awards and options exercised, including related taxes (shares)	'	'	-15,000	'	'	'	-5,874,000
Common stock awards and options exercised, including related taxes	302	'	'	86	'	'	216
Other (shares)	'	'	'	'	'	'	-12,000
Ending balance at Sep. 30, 2013	20,430	490	504	9,753	12,963	-114	-3,166
Ending balance (shares) at Sep. 30, 2013	'	'	503,885,000	'	'	'	62,587,000
Beginning balance at Jun. 30, 2013	'	'	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net income	540	'	'	'	'	'	'
Cash dividends declared:	'	'	'	'	'	'	'
Common stock	'	'	'	'	-115	'	'
Ending balance at Sep. 30, 2013	$20,430	'	'	'	$12,963	'	'

Consolidated_Statement_of_Chan1

Consolidated Statement of Changes In Shareholders' Equity (Unaudited) (Parenthetical) (USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Statement of Stockholders' Equity [Abstract]	'	'
Cash dividends declared (in dollars per share)	$0.78	$0.72
Common stock awards and options exercised, related taxes	$42	($8)

Consolidated_Statement_of_Cash

Consolidated Statement of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating Activities:	'	'
Net income	$1,583	$1,591
Adjustments to reconcile net income to net cash provided by (used in) operating activities:	'	'
Deferred income tax expense (benefit)	77	-44
Amortization of other intangible assets	160	145
Other non-cash adjustments for depreciation, amortization and accretion	324	172
(Gains) losses related to investment securities, net	9	-2
Change in trading account assets, net	-279	96
Change in accrued income receivable, net	-124	-111
Change in collateral deposits, net	-2,765	-1,219
Change in unrealized losses on foreign exchange derivatives, net	1,304	483
Change in other assets, net	-888	343
Change in accrued expenses and other liabilities, net	-442	341
Claims resolution	0	-362
Other, net	-9	-33
Net cash (used in) provided by operating activities	-1,050	1,400
Investing Activities:	'	'
Net decrease in interest-bearing deposits with banks	12,127	27,303
Net increase in securities purchased under resale agreements	-811	-1,219
Proceeds from sales of available-for-sale securities	8,090	4,209
Proceeds from maturities of available-for-sale securities	29,540	33,047
Purchases of available-for-sale securities	-29,005	-44,355
Proceeds from maturities of available-for-sale securities	1,474	2,561
Purchases of held-to-maturity securities	-6,424	-7
Net increase in loans	-3,304	-4,042
Purchases of equity investments and other long-term assets	-100	-69
Divestitures	18	0
Purchases of premises and equipment	-259	-254
Other, net	84	105
Net cash provided by investing activities	11,430	17,279
Financing Activities:	'	'
Net increase (decrease) in time deposits	-14,750	2,143
Net increase (decrease) in all other deposits	4,768	-13,141
Net increase (decrease) in short-term borrowings	967	-1,211
Proceeds from issuance of long-term debt, net of issuance costs	1,492	0
Payments for long-term debt and obligations under capital leases	-127	-1,768
Proceeds from issuance of preferred stock	0	488
Proceeds related to common stock awards and option exercises	584	438
Purchases of common stock	-1,480	-960
Repurchases of common stock for employee tax withholding	-163	-88
Payments for cash dividends	-365	-341
Net cash used in financing activities	-9,074	-14,440
Net increase	1,306	4,239
Cash and due from banks at beginning of period	2,590	2,193
Cash and due from banks at end of period	$3,896	$6,432

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accounting and financial reporting policies of State Street Corporation conform to U.S. generally accepted accounting principles, referred to as GAAP. State Street Corporation, the parent company, is a financial holding company headquartered in Boston, Massachusetts. Unless otherwise indicated or unless the context requires otherwise, all references in these condensed notes to consolidated financial statements to “State Street,” “we,” “us,” “our” or similar references mean State Street Corporation and its subsidiaries on a consolidated basis. Our principal banking subsidiary is State Street Bank and Trust Company, or State Street Bank.
	We have two lines of business:
	Investment Servicing provides services for mutual funds, collective investment funds and other investment pools, corporate and public retirement plans, insurance companies, foundations and endowments worldwide. Products include custody, product- and participant-level accounting, daily pricing and administration; master trust and master custody; record-keeping; foreign exchange, brokerage and other trading services; securities finance; deposit and short-term investment facilities; loans and lease financing; investment manager and alternative investment manager operations outsourcing; and performance, risk and compliance analytics to support institutional investors.
	Investment Management, through State Street Global Advisors, or SSgA, provides a broad range of investment management strategies, specialized investment management advisory services and other financial services, such as securities finance, for corporations, public funds, and other sophisticated investors. Management strategies offered by SSgA include passive and active, such as enhanced indexing, using quantitative and fundamental methods for both U.S. and non-U.S. equity and fixed-income securities. SSgA also offers exchange-traded funds.
	The consolidated financial statements accompanying these condensed notes are unaudited. In the opinion of management, all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair statement of the consolidated results of operations in these financial statements, have been made. Certain previously reported amounts presented in this Form 10-Q have been reclassified to conform to current-period presentation. Events occurring subsequent to the date of our consolidated statement of condition were evaluated for potential recognition or disclosure in our consolidated financial statements through the date we filed this Form 10-Q with the SEC.
	The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions in the application of certain of our significant accounting policies that may materially affect the reported amounts of assets, liabilities, equity, revenue and expenses. As a result of unanticipated events or circumstances, actual results could differ from those estimates. Amounts dependent on subjective or complex judgments in the application of accounting policies considered by management to be relatively more significant in this regard are those associated with our accounting for fair-value measurements; other-than-temporary impairment of investment securities; and impairment of goodwill and other intangible assets. Among other effects, unanticipated events or circumstances could result in future impairment of investment securities, goodwill or other intangible assets.
	Our consolidated statement of condition at December 31, 2012 included in the accompanying consolidated financial statements was derived from the audited financial statements at that date, but does not include all notes required by GAAP for a complete set of financial statements. The accompanying consolidated financial statements and these condensed notes should be read in conjunction with the financial and risk factors information included in our 2012 Form 10-K, which we previously filed with the SEC.
	Recent Accounting Developments:
	In June 2013, the FASB issued an amendment to GAAP that prescribes certain criteria for an entity to qualify as an investment company.  The amendment is not expected to significantly change which entities qualify to use specialized accounting for investment companies, but introduces new disclosure requirements that apply to all investment companies, and revises the criteria used to measure certain interests in investment companies.  We are not an investment company, but we are affiliated with investment companies in our role as an asset manager, and we provide accounting and reporting services to investment companies in our role as an asset servicer.  The amendment is effective, for State Street, for interim and annual periods beginning on January 1, 2014.  While the amendment could affect how we measure our interests in investment companies, our adoption of the amendment is not expected to have a material effect on our consolidated financial statements.
	In July 2013, the FASB issued an amendment to GAAP that requires a liability associated with an unrecognized tax benefit, or a portion of that unrecognized tax benefit, to be presented in the financial statements as a reduction of a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. The amendment is effective, for State Street, for interim and annual periods beginning on January 1, 2014, and is required to be applied on a prospective basis. Our adoption of the amendment is not expected to have a material effect on our consolidated financial statements.

Fair_Value

Fair Value	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value	'
	Fair Value
	Fair-Value Measurements:
	We carry trading account assets, investment securities available for sale and various types of derivative financial instruments at fair value in our consolidated statement of condition on a recurring basis. Changes in the fair values of these financial assets and liabilities are recorded either as components of our consolidated statement of income or as components of accumulated other comprehensive income within shareholders' equity in our consolidated statement of condition.
	We measure fair value for the above-described financial assets and liabilities in accordance with GAAP that governs the measurement of the fair value of financial instruments. Management believes that its valuation techniques and underlying assumptions used to measure fair value conform to the provisions of GAAP. We categorize the financial assets and liabilities that we carry at fair value based on a prescribed three-level valuation hierarchy. The hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (level 1) and the lowest priority to valuation methods using significant unobservable inputs (level 3). If the inputs used to measure a financial asset or liability cross different levels of the hierarchy, categorization is based on the lowest-level input that is most significant to the fair-value measurement. Management's assessment of the significance of a particular input to the overall fair-value measurement of a financial asset or liability requires judgment, and considers factors specific to that asset or liability. The three valuation levels are described below.
	Level 1. Financial assets and liabilities with values based on unadjusted quoted prices for identical assets or liabilities in an active market. Fair value is measured using unadjusted quoted prices in active markets for identical securities. Our level-1 financial assets and liabilities primarily include positions in U.S. government securities and highly liquid U.S. and non-U.S. government fixed-income securities. We may carry U.S. government securities in our available-for-sale portfolio in connection with our asset-and-liability management activities. Our level-1 financial assets also include active exchange-traded equity securities.
	Level 2. Financial assets and liabilities with values based on quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the asset or liability. Level-2 inputs include the following:
	•	Quoted prices for similar assets or liabilities in active markets;
	•	Quoted prices for identical or similar assets or liabilities in non-active markets;
	•	Pricing models whose inputs are observable for substantially the full term of the asset or liability; and
	•	Pricing models whose inputs are derived principally from, or corroborated by, observable market information through correlation or other means for substantially the full term of the asset or liability.
	Our level-2 financial assets and liabilities primarily include trading account assets and fixed-income investment securities available for sale, as well as various types of foreign exchange and interest-rate derivative instruments.
	Fair value for our investment securities available for sale categorized in level 2 is measured primarily using information obtained from independent third parties. This third-party information is subject to review by management as part of a validation process, which includes obtaining an understanding of the underlying assumptions and the level of market participant information used to support those assumptions. In addition, management compares significant assumptions used by third parties to available market information. Such information may include known trades or, to the extent that trading activity is limited, comparisons to market research information pertaining to credit expectations, execution prices and the timing of cash flows, and where information is available, back-testing.
	Derivative instruments categorized in level 2 predominantly represent foreign exchange contracts used in our trading activities, for which fair value is measured using discounted cash-flow techniques, with inputs consisting of observable spot and forward points, as well as observable interest-rate curves. With respect to derivative instruments, we evaluate the impact on valuation of the credit risk of our counterparties and our own credit risk. We consider factors such as the likelihood of default by us and our counterparties, our current and potential future net exposures and remaining maturities in determining the fair value. Valuation adjustments associated with derivative instruments were not material to those instruments in the three and nine months ended September 30, 2013 or 2012.
	Level 3. Financial assets and liabilities with values based on prices or valuation techniques that require inputs that are both unobservable in the market and significant to the overall measurement of fair value. These inputs reflect management's judgment about the assumptions that a market participant would use in pricing the financial asset or liability, and are based on the best available information, some of which is internally developed. The following provides a more detailed discussion of our financial assets and liabilities that we may categorize in level 3 and the related valuation methodology.
	•	The fair value of our investment securities categorized in level 3 is measured using information obtained from third-party sources, typically non-binding broker or dealer quotes, or through the use of internally-developed pricing models. Management has evaluated its methodologies used to measure fair value, but has considered the level of observable market information to be insufficient to categorize the securities in level 2.
	•	The fair value of foreign exchange contracts, primarily options, is measured using an option-pricing model. Because of a limited number of observable transactions, certain model inputs are not observable, such as implied volatility surface, but are derived from observable market information.
	•	The fair value of certain interest-rate caps with long-dated maturities, is measured using a matrix-pricing approach. Observable market prices are not available for these derivatives, so extrapolation is necessary to value these instruments, since they have a strike and/or maturity outside of the matrix.
	Our level-3 financial assets and liabilities are similar in structure and profile to our level-1 and level-2 financial instruments, but they trade in less-liquid markets, and the measurement of their fair value is inherently more difficult. As of September 30, 2013, on a gross basis, we categorized in level 3 approximately 7% and 1% of our financial assets and liabilities, respectively, carried at fair value on a recurring basis. We generally determine the fair value of our level-3 financial assets and liabilities using pricing information obtained from third-party sources, typically non-binding broker and dealer quotes, and, to a lesser extent, using internally-developed pricing models. The fair value of investment securities categorized in level 3 that was measured using non-binding quotes and internally-developed pricing-model inputs composed approximately 98% and 2%, respectively, of the total fair value of the investment securities categorized in level 3 as of September 30, 2013.
	The process used to measure the fair value of our level-3 financial assets and liabilities is overseen by a valuation group within Corporate Finance, independent of the business units that carry the assets and liabilities. This function, which develops and manages the valuation process, reports to State Street's Valuation Committee. The Valuation Committee, composed of senior management from independent business units, Enterprise Risk Management and Corporate Finance, oversees adherence to State Street's valuation policies.
	The valuation group performs independent validation of the pricing information obtained from third-party sources in order to evaluate reasonableness and consistency with market experience in similar asset classes. Monthly analyses include a review of price changes relative to overall trends, credit analysis and other relevant procedures (discussed below). In addition, prices for level-3 securities carried in our investment portfolio are tested on a sample basis based on unexpected pricing movements. These sample prices are then corroborated through price recalculations, when applicable, using available market information, which is obtained independent of the third-party pricing source. The recalculated prices are compared to market-research information pertaining to credit expectations, execution prices and the timing of cash flows, and where information is available, back-testing. If a difference is identified and it is determined that there is a significant impact requiring an adjustment, the adjustment is presented to the Valuation Committee for review and consideration.
	Independent validation is also performed on fair-value measurements determined using internally-developed pricing models. The pricing models are subject to independent validation through our Model Assessment Committee, a corporate risk oversight committee that provides technical support and input to the Valuation Committee. This validation process incorporates a review of a diverse set of model and trade parameters across a broad range of values in order to evaluate the model's suitability for valuation of a particular financial instrument type, as well as the model's accuracy in reflecting the characteristics of the related financial asset or liability and its significant risks. Inputs and assumptions, including any price-valuation adjustments, are developed by the business units and independently reviewed by the valuation group. Model valuations are compared to available market information including appropriate proxy instruments and other benchmarks to highlight abnormalities for further investigation.
	Measuring fair value requires the exercise of management judgment. The level of subjectivity and the degree of management judgment required is more significant for financial instruments whose fair value is measured using inputs that are not observable. The areas requiring significant judgment are identified, documented and reported to the Valuation Committee as part of the valuation control framework. We believe that our valuation methods are appropriate; however, the use of different methodologies or assumptions, particularly as they apply to level-3 financial assets and liabilities, could materially affect fair-value measurements as of the reporting date.
	The following tables present information with respect to our financial assets and liabilities carried at fair value in our consolidated statement of condition on a recurring basis as of the dates indicated. No transfers of financial assets or liabilities between levels 1 and 2 occurred during the nine months ended September 30, 2013 or the year ended December 31, 2012.
		Fair-Value Measurements on a Recurring Basis
		as of September 30, 2013
	(In millions)	Quoted Market			Pricing Methods				Pricing Methods				Impact of Netting(1)			Total Net
		Prices in Active			with Significant				with Significant							Carrying Value
		Markets			Observable				Unobservable							in Consolidated
		(Level 1)			Market Inputs				Market Inputs							Statement of
					(Level 2)				(Level 3)							Condition
	Assets:
	Trading account assets:
	U.S. government securities	$	20													$	20
	Non-U.S. government securities	392														392
	Other	66			$	438										504
	Total trading account assets	478			438											916
	Investment securities available for sale:
	U.S. Treasury and federal agencies:
	Direct obligations	—			738											738
	Mortgage-backed securities	—			23,834				$	741						24,575
	Asset-backed securities:
	Student loans	—			14,503				368							14,871
	Credit cards	—			8,602				24							8,626
	Sub-prime	—			1,266				—							1,266
	Other	—			551				4,350							4,901
	Total asset-backed securities	—			24,922				4,742							29,664
	Non-U.S. debt securities:
	Mortgage-backed securities	—			10,661				340							11,001
	Asset-backed securities	—			4,668				799							5,467
	Government securities	—			3,541				—							3,541
	Other	—			4,159				441							4,600
	Total non-U.S. debt securities	—			23,029				1,580							24,609
	State and political subdivisions	—			9,254				44							9,298
	Collateralized mortgage obligations	—			4,971				187							5,158
	Other U.S. debt securities	—			5,036				9							5,045
	U.S. equity securities	—			39				—							39
	Non-U.S. equity securities	—			2				—							2
	U.S. money-market mutual funds	—			680				—							680
	Non-U.S. money-market mutual funds	—			174				—							174
	Total investment securities available for sale	—			92,679				7,303							99,982
	Other assets:
	Derivative instruments:
	Foreign exchange contracts	—			10,289				77				$	(6,060	)	4,306
Interest-rate contracts	—			58				—				(45		)	13
Other	—			1				—				—			1
Total derivative instruments	—			10,348				77				(6,105		)	4,320
Other	101			—				—				—			101
Total assets carried at fair value	$	579		$	103,465			$	7,380			$	(6,105	)	$	105,319
Liabilities:
Accrued expenses and other liabilities:
Derivative instruments:
Foreign exchange contracts				$	10,206			$	55			$	(4,211	)	$	6,050
Interest-rate contracts				307				—				(59		)	248
Other				—				9				—			9
Total derivative instruments				10,513				64				(4,270		)	6,307
Other	$	101		—				—				—			101
Total liabilities carried at fair value	$	101		$	10,513			$	64			$	(4,270	)	$	6,408
(1) Represents counterparty netting against level-2 financial assets and liabilities, where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $2.30 billion and $468 million, respectively, for cash collateral received from and provided to derivative counterparties.
	Fair-Value Measurements on a Recurring Basis
	as of December 31, 2012
(In millions)	Quoted Market			Pricing Methods				Pricing Methods				Impact of Netting(1)			Total Net
	Prices in Active			with Significant				with Significant							Carrying Value
	Markets			Observable				Unobservable							in Consolidated
	(Level 1)			Market Inputs				Market Inputs							Statement of
				(Level 2)				(Level 3)							Condition
Assets:
Trading account assets:
U.S. government securities	$	20													$	20
Non-U.S. government securities	391														391
Other	71			$	155										226
Total trading account assets	482			155											637
Investment securities available for sale:
U.S. Treasury and federal agencies:
Direct obligations	3			838											841
Mortgage-backed securities	—			31,387				$	825						32,212
Asset-backed securities:
Student loans	—			15,833				588							16,421
Credit cards	—			9,919				67							9,986
Sub-prime	—			1,399				—							1,399
Other	—			683				3,994							4,677
Total asset-backed securities	—			27,834				4,649							32,483
Non-U.S. debt securities:
Mortgage-backed securities	—			10,850				555							11,405
Asset-backed securities	—			5,694				524							6,218
Government securities	—			3,199				—							3,199
Other	—			4,166				140							4,306
Total non-U.S. debt securities	—			23,909				1,219							25,128
State and political subdivisions	—			7,503				48							7,551
Collateralized mortgage obligations	—			4,837				117							4,954
Other U.S. debt securities	—			5,289				9							5,298
U.S. equity securities	—			31				—							31
Non-U.S. equity securities	—			1				—							1
U.S. money-market mutual funds	—			1,062				—							1,062
Non-U.S. money-market mutual funds	—			121				—							121
Total investment securities available for sale	3			102,812				6,867							109,682
Other assets:
Derivatives instruments:
Foreign exchange contracts	—			9,265				113				$	(4,981	)	4,397
Interest-rate contracts	—			223				—				(64		)	159
Total derivative instruments	—			9,488				113				(5,045		)	4,556
Other	66			2				—				—			68
Total assets carried at fair value	$	551		$	112,457			$	6,980			$	(5,045	)	$	114,943
Liabilities:
Accrued expenses and other liabilities:
Derivative instruments:
Foreign exchange contracts				$	8,978			$	106			$	(4,052	)	$	5,032
Interest-rate contracts				345				—				(19		)	326
Other				—				9				—			9
Total derivative instruments				9,323				115				(4,071		)	5,367
Other	$	66		—				—				—			66
Total liabilities carried at fair value	$	66		$	9,323			$	115			$	(4,071	)	$	5,433
(1) Represents counterparty netting against level-2 financial assets and liabilities, where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $1.45 billion and $478 million, respectively, for cash collateral received from and provided to derivative counterparties.
The following tables present activity related to our level-3 financial assets and liabilities during the three and nine months ended September 30, 2013 and 2012, respectively. Transfers into and out of level 3 are reported as of the beginning of the period. In both the three and nine months ended September 30, 2013 and 2012, transfers out of level 3 were substantially related to certain asset-backed securities and non-U.S. debt securities, for which fair value was measured using prices for which observable market information became available.
	Fair-Value Measurements Using Significant Unobservable Inputs
	Three Months Ended September 30, 2013
	Fair			Transfers				Transfers				Total Realized and						Purchases		Issuances		Sales				Settlements			Fair Value as of			Change in
	Value as of			into				out of				Unrealized Gains (Losses)																	30-Sep-13			Unrealized
	June 30,			Level 3				Level 3																								Gains
	2013																															(Losses)
																																Related to
																																Financial
																																Instruments
																																Held as of
																																September 30,
(In millions)												Recorded			Recorded																	2013
												in			in Other
												Revenue			Comprehensive
															Income
Assets:
Investment securities available for sale:
U.S. Treasury and federal agencies, mortgage-backed securities	$	864						$	(93	)					$	(1	)									$	(29	)	$	741
Asset-backed securities:
Student loans	380							—							(2		)									(10		)	368
Credit cards	24							—							—											—			24
Other	3,848							—				$	13		(5		)	$	793			$	(24	)		(275		)	4,350
Total asset-backed securities	4,252							—				13			(7		)	793				(24		)		(285		)	4,742
Non-U.S. debt securities:
Mortgage-backed securities	328							—				—			(1		)	—				—				13			340
Asset-backed securities	756							(104		)		1			1			164				—				(19		)	799
Other	281							—				—			(1		)	149				—				12			441
Total non-U.S. debt securities	1,365							(104		)		1			(1		)	313				—				6			1,580
State and political subdivisions	45							—				—			(1		)	—								—			44
Collateralized mortgage obligations	238			$	15			(100		)		—			(5		)	50				—				(11		)	187
Other U.S. debt securities	9			—				—				—			—			—				—				—			9
Total investment securities available for sale	6,773			15				(297		)		14			(15		)	1,156				(24		)		(319		)	7,303
Other assets:
Derivative instruments, Foreign exchange contracts	121			—				—				(21		)	—			7				—				(30		)	77			$	(16	)
Total assets carried at fair value	$	6,894		$	15			$	(297	)		$	(7	)	$	(15	)	$	1,163	—		$	(24	)		$	(349	)	$	7,380		$	(16	)
	Fair-Value Measurements Using Significant Unobservable Inputs
	Three Months Ended September 30, 2013
	Fair			Transfers			Transfers			Total Realized and						Purchases		Issuances		Sales		Settlements				Fair Value as of			Change in
	Value as of			into			out of			Unrealized (Gains) Losses																30-Sep-13			Unrealized
	June 30,			Level 3			Level 3																						(Gains)
	2013																												Losses
																													Related to
																													Financial
																													Instruments
																													Held as of
																													September 30,
(In millions)										Recorded				Recorded															2013
										in				in Other
										Revenue				Comprehensive
														Income
Liabilities:
Accrued expenses and other liabilities:
Derivative instruments:
Foreign exchange contracts	$	108								$	(17	)						$	5			$	(41	)		$	55		$	(15	)
Other	9									—								—				—				9			—
Total derivative instruments	117									(17		)						5				(41		)		64			(15		)
Total liabilities carried at fair value	$	117		—			—			$	(17	)		—		—		$	5	—		$	(41	)		$	64		$	(15	)
	Fair-Value Measurements Using Significant Unobservable Inputs
	Nine Months Ended September 30, 2013
	Fair			Transfers				Transfers				Total Realized and						Purchases		Issuances		Sales				Settlements			Fair			Change in
	Value as of			into				out of				Unrealized Gains (Losses)																	Value as of			Unrealized
	December 31,			Level 3				Level 3																					September 30,			Gains
	2012																												2013			(Losses)
																																Related to
																																Financial
																																Instruments
																																Held as of
																																September 30,
(In millions)												Recorded			Recorded																	2013
												in			in Other
												Revenue			Comprehensive
															Income
Assets:
Investment securities available for sale:
U.S. Treasury and federal agencies, mortgage-backed securities	$	825						$	(92	)					$	(1	)	$	92							$	(83	)	$	741
Asset-backed securities:
Student loans	588							(175		)		$	1		6			—				$	(26	)		(26		)	368
Credit cards	67							—				—			—			—				—				(43		)	24
Other	3,994							—				40			25			1,358				(33		)		(1,034		)	4,350
Total asset-backed securities	4,649							(175		)		41			31			1,358				(59		)		(1,103		)	4,742
Non-U.S. debt securities:
Mortgage-backed securities	555							(208		)		—			(1		)	—				—				(6		)	340
Asset-backed securities	524			$	139			(181		)		4			2			399				—				(88		)	799
Other	140			—				(40		)		—			—			328				—				13			441
Total non-U.S. debt securities	1,219			139				(429		)		4			1			727				—				(81		)	1,580
State and political subdivisions	48			—				—				—			(1		)	—				—				(3		)	44
Collateralized mortgage obligations	117			15				(100		)		1			(5		)	190				—				(31		)	187
Other U.S. debt securities	9			—				—				—			—			—				—				—			9
Total investment securities available for sale	6,867			154				(796		)		46			25			2,367				(59		)		(1,301		)	7,303
Other assets:
Derivative instruments, Foreign exchange contracts	113			—				—				119			—			25				—				(180		)	77			$	29
Total assets carried at fair value	$	6,980		$	154			$	(796	)		$	165		$	25		$	2,392	—		$	(59	)		$	(1,481	)	$	7,380		$	29
	Fair-Value Measurements Using Significant Unobservable Inputs
	Nine Months Ended September 30, 2013
	Fair			Transfers			Transfers			Total Realized and						Purchases		Issuances		Sales		Settlements				Fair			Change in
	Value as of			into			out of			Unrealized (Gains) Losses																Value as of			Unrealized
	December 31,			Level 3			Level 3																			September 30,			(Gains)
	2012																									2013			Losses
																													Related to
																													Financial
																													Instruments
																													Held as of
																													September 30,
(In millions)										Recorded				Recorded															2013
										in				in Other
										Revenue				Comprehensive
														Income
Liabilities:
Accrued expenses and other liabilities:
Derivative instruments:
Foreign exchange contracts	$	106								$	59							$	24			$	(134	)		$	55		$	15
Other	9									—								—				—				9			—
Total derivative instruments	115									59								24				(134		)		64			15
Total liabilities carried at fair value	$	115		—			—			$	59			—		—		$	24	—		$	(134	)		$	64		$	15
	Fair-Value Measurements Using Significant Unobservable Inputs
	Three Months Ended September 30, 2012
	Fair			Transfers				Transfers				Total Realized and						Purchases		Issuances		Sales				Settlements			Fair			Change in
	Value as of June 30,			into				out of				Unrealized Gains (Losses)																	Value as of			Unrealized
	2012			Level 3				Level 3																					30-Sep-12			Gains
																																(Losses)
																																Related to
																																Financial
																																Instruments
																																Held as of
																																September 30,
(In millions)												Recorded			Recorded																	2012
												in			in Other
												Revenue			Comprehensive
															Income
Assets:
Investment securities available for sale:
U.S. Treasury and federal agencies:
Direct obligations
Mortgage-backed securities	$	933													$	3										$	(30	)	$	906
Asset-backed securities:
Student loans	484											$	1		5											(12		)	478
Credit cards	274							$	(36	)		1			(1		)									—			238
Other	3,094			$	12			(11		)		10			14			$	608							(267		)	3,460
Total asset-backed securities	3,852			12				(47		)		12			18			608								(279		)	4,176
Non-U.S. debt securities:
Mortgage-backed securities	273			—				(147		)		—			—			156								3			285
Asset-backed securities	1,362			—				(676		)		1			4			—								(14		)	677
Other	1			—				—				—			—			193								—			194
Total non-U.S. debt securities	1,636			—				(823		)		1			4			349								(11		)	1,156
State and political subdivisions	49			—				—				—			(1		)	—								—			48
Collateralized mortgage obligations	301			—				(123		)		168			1			—				$	(45	)		(178		)	124
Other U.S. debt securities	—			9				—				—			—			—				—				—			9
Total investment securities available for sale	6,771			21				(993		)		181			25			957				(45		)		(498		)	6,419
Other assets:
Derivative instruments, Foreign exchange contracts	160			—				—				(69		)	—			75				—				(67		)	99			$	(47	)
Total assets carried at fair value	$	6,931		$	21			$	(993	)		$	112		$	25		$	1,032	—		(45		)		$	(565	)	$	6,518		$	(47	)
	Fair-Value Measurements Using Significant Unobservable Inputs
	Three Months Ended September 30, 2012
	Fair			Transfers			Transfers			Total Realized and						Purchases		Issuances		Sales		Settlements				Fair			Change in
	Value as of June 30,			into			out of			Unrealized (Gains) Losses																Value as of			Unrealized
	2012			Level 3			Level 3																			September 30,			(Gains)
																										2012			Losses
																													Related to
																													Financial
																													Instruments
																													Held as of
																													September 30,
(In millions)										Recorded				Recorded															2012
										in				in Other
										Revenue				Comprehensive
														Income
Liabilities:
Accrued expenses and other liabilities:
Derivative instruments:
Foreign exchange contracts	$	157								$	(58	)						$	76			$	(75	)		$	100		$	(43	)
Other	9									—								—				—				9			—
Total derivative instruments	166									(58		)						76				(75		)		109			(43		)
Total liabilities carried at fair value	$	166		—			—			$	(58	)		—		—		$	76	—		$	(75	)		$	109		$	(43	)
	Fair-Value Measurements Using Significant Unobservable Inputs
	Nine Months Ended September 30, 2012
	Fair			Transfers				Transfers				Total Realized and						Purchases		Issuances		Sales				Settlements			Fair			Change in
	Value as of December 31,			into				out of				Unrealized Gains (Losses)																	Value as of			Unrealized
	2011			Level 3				Level 3																					September 30,			Gains
																													2012			(Losses)
																																Related to
																																Financial
																																Instruments
																																Held as of
																																September 30,
(In millions)												Recorded			Recorded																	2012
												in			in Other
												Revenue			Comprehensive
															Income
Assets:
Investment securities available for sale:
U.S. Treasury and federal agencies:
Mortgage-backed securities	$	1,189		$	50			$	(251	)					$	3										$	(85	)	$	906
Asset-backed securities:
Student loans	860			—				(341		)		$	2		(5		)									(38		)	478
Credit cards	91			21				(36		)		4			(5		)	$	224			$	(61	)		—			238
Other	2,798			12				(11		)		31			39			1,177				(12		)		(574		)	3,460
Total asset-backed securities	3,749			33				(388		)		37			29			1,401				(73		)		(612		)	4,176
Non-U.S. debt securities:
Mortgage-backed securities	1,457			—				(1,642		)		—			3			463				—				4			285
Asset-backed securities	1,768			—				(2,243		)		1			4			1,206				—				(59		)	677
Other	71			—				(372		)		—			(3		)	500				—				(2		)	194
Total non-U.S. debt securities	3,296			—				(4,257		)		1			4			2,169				—				(57		)	1,156
State and political subdivisions	50			—				—				—			—			—								(2		)	48
Collateralized mortgage obligations	227			44				(314		)		369			1			283				(45		)		(441		)	124
Other U.S. debt securities	2			9				—				—			—			—				—				(2		)	9
Total investment securities available for sale	8,513			136				(5,210		)		407			37			3,853				(118		)		(1,199		)	6,419
Other assets:
Derivative instruments:
Foreign exchange contracts	168			—				—				(127		)	—			162				—				(104		)	99			$	(71	)
Interest-rate contracts	10			—				—				(10		)	—			—				—				—			—			—
Total derivative instruments	178			—				—				(137		)	—			162				—				(104		)	99			(71		)
Total assets carried at fair value	$	8,691		$	136			$	(5,210	)		$	270		$	37		$	4,015	—		$	(118	)		$	(1,303	)	$	6,518		$	(71	)
	Fair-Value Measurements Using Significant Unobservable Inputs
	Nine Months Ended September 30, 2012
	Fair			Transfers			Transfers			Total Realized and						Purchases		Issuances		Sales		Settlements				Fair			Change in
	Value as of December 31,			into			out of			Unrealized (Gains) Losses																Value as of			Unrealized
	2011			Level 3			Level 3																			September 30,			(Gains)
																										2012			Losses
																													Related to
																													Financial
																													Instruments
																													Held as of
																													September 30,
(In millions)										Recorded				Recorded															2012
										in				in Other
										Revenue				Comprehensive
														Income
Liabilities:
Accrued expenses and other liabilities:
Derivative instruments:
Foreign exchange contracts	$	161								$	(131	)						$	162			$	(92	)		$	100		$	(70	)
Interest-rate contracts	11									(11		)						—				—				—			—
Other	9									—								—				—				9			—
Total derivative instruments	181									(142		)						162				(92		)		109			(70		)
Other	20									—								—				(20		)		—
Total liabilities carried at fair value	$	201		—			—			$	(142	)		—		—		$	162	—		$	(112	)		$	109		$	(70	)
The following table presents total realized and unrealized gains and losses, for the periods indicated, that were recorded in revenue for our level-3 financial assets and liabilities:
	Three Months Ended September 30,														Nine Months Ended September 30,
	Total Realized and							Change in							Total Realized and					Change in
	Unrealized Gains							Unrealized Gains							Unrealized Gains					Unrealized Gains
	(Losses) Recorded							(Losses) Related to							(Losses) Recorded					(Losses) Related to
	in Revenue							Financial							in Revenue					Financial
								Instruments Held as of												Instruments Held as of
								September 30,												September 30,
(In millions)	2013			2012				2013				2012			2013			2012		2013			2012
Fee revenue:
Trading services	$	(4	)	$	(11	)		$	(1	)		$	(4	)	$	60		$	5	$	14		$	(1	)
Total fee revenue	(4		)	(11		)		(1		)		(4		)	60			5		14			(1		)
Net interest revenue	14			181				—				—			46			407		—			—
Total revenue	$	10		$	170			$	(1	)		(4		)	$	106		$	412	$	14		$	(1	)
The following table presents quantitative information, as of the dates indicated, about the valuation techniques and significant unobservable inputs used in the valuation of our level-3 financial assets and liabilities measured at fair value on a recurring basis for which we use internally-developed pricing models. The significant unobservable inputs for our level-3 financial assets and liabilities whose fair value is measured using pricing information from non-binding broker or dealer quotes are not included in the table, as the specific inputs applied are not provided by the broker/dealer.
		Quantitative Information about Level-3 Fair-Value Measurements
		Fair Value											Weighted-Average
(Dollars in millions)		As of			As of				Valuation Technique		Significant		As of September 30, 2013		As of December 31, 2012
		30-Sep-13			31-Dec-12						Unobservable Input
Significant unobservable inputs readily available to State Street:
Assets:
Asset-backed securities, student loans		$	13		$	12			Discounted cash flows		Credit spread		4.4	%	6.7	%
Asset-backed securities, credit cards		24			67				Discounted cash flows		Credit spread		2.1		7.1
Asset-backed securities, other		101			103				Discounted cash flows		Credit spread		1		1.5
State and political subdivisions		44			48				Discounted cash flows		Credit spread		2		1.9
Derivative instruments, foreign exchange contracts		77			113				Option model		Volatility		13.3		9.8
Total		$	259		$	343
Liabilities:
Derivative instruments, foreign exchange contracts		$	55		$	106			Option model		Volatility		13.1		9.8
Derivative instruments, other		9			9				Discounted cash flows		Participant redemptions		7.1		6.7
Total		$	64		$	115
The following tables present information with respect to the composition of our level-3 financial assets and liabilities, by availability of significant unobservable inputs, as of the dates indicated:
30-Sep-13		Significant Unobservable Inputs Readily Available to State Street(1)			Significant Unobservable Inputs Not Developed by State Street and Not Readily Available(2)				Total Assets and Liabilities with Significant Unobservable Inputs
(In millions)
Assets:
U.S. Treasury and federal agencies, mortgage-backed securities		$	—		$	741			$	741
Asset-backed securities, student loans		13			355				368
Asset-backed securities, credit cards		24			—				24
Asset-backed securities, other		101			4,249				4,350
Non-U.S. debt securities, mortgage-backed securities		—			340				340
Non-U.S. debt securities, asset-backed securities		—			799				799
Non-U.S. debt securities, other		—			441				441
State and political subdivisions		44			—				44
Collateralized mortgage obligations		—			187				187
Other U.S.debt securities		—			9				9
Derivative instruments, foreign exchange contracts		77			—				77
Total		$	259		$	7,121			$	7,380
Liabilities:
Derivative instruments, foreign exchange contracts		$	55		—				$	55
Derivative instruments, other		9			—				9
Total		$	64		—				$	64
31-Dec-12		Significant Unobservable Inputs Readily Available to State Street(1)			Significant Unobservable Inputs Not Developed by State Street and Not Readily Available(2)				Total Assets and Liabilities with Significant Unobservable Inputs
(In millions)
Assets:
U.S. Treasury and federal agencies, mortgage-backed securities		$	—		$	825			$	825
Asset-backed securities, student loans		12			576				588
Asset-backed securities, credit cards		67			—				67
Asset-backed securities, other		103			3,891				3,994
Non-U.S. debt securities, mortgage-backed securities		—			555				555
Non-U.S. debt securities, asset-backed securities		—			524				524
Non-U.S. debt securities, other		—			140				140
State and political subdivisions		48			—				48
Collateralized mortgage obligations		—			117				117
Other U.S.debt securities		—			9				9
Derivative instruments, foreign exchange contracts		113			—				113
Total		$	343		$	6,637			$	6,980
Liabilities:
Derivative instruments, foreign exchange contracts		$	106		—				$	106
Derivative instruments, other		9			—				9
Total		$	115		—				$	115
(1) Information with respect to these model-priced financial assets and liabilities is provided in the preceding table.
(2) Fair value for these financial assets is measured using non-binding broker or dealer quotes.
Internally-developed pricing models used to measure the fair value of our level-3 financial assets and liabilities incorporate discounted cash-flow and option-modeling techniques. Use of these techniques requires the determination of relevant inputs and assumptions, some of which represent significant unobservable inputs as indicated in the preceding table. Accordingly, changes in these unobservable inputs may have a significant impact on fair value.
Certain of these unobservable inputs will, in isolation, have a directionally consistent impact on the fair value of the instrument for a given change in that input. Alternatively, the fair value of the instrument may move in an opposite direction for a given change in another input. Where multiple inputs are used within the valuation technique of an asset or liability, a change in one input in a certain direction may be offset by an opposite change in another input, resulting in a potentially muted impact on the overall fair value of that particular instrument. Additionally, a change in one unobservable input may result in a change to another unobservable input (that is, changes in certain inputs are interrelated to one another), which may counteract or magnify the fair-value impact.
For recurring level-3 fair-value measurements for which significant unobservable inputs are readily available to State Street as of September 30, 2013, the sensitivity of the fair-value measurement to changes in significant unobservable inputs, and a description of any interrelationships between those unobservable inputs, is described below; however, we rarely experience a situation in which those unobservable inputs change in isolation:
•	The significant unobservable input used in the measurement of the fair value of our asset-backed securities and investment securities issued by state and political subdivisions is the credit spread. Significant increases (decreases) in the credit spread would result in measurements of significantly lower (higher) fair value.
•	The significant unobservable input used in the measurement of the fair value of our foreign exchange option contracts is the implied volatility surface. A significant increase (decrease) in the implied volatility surface would result in measurements of significantly higher (lower) fair value.
•	The significant unobservable input used in the measurement of the fair value of our other derivative instruments, specifically stable value wrap contracts, is participant redemptions. Increased volatility of redemptions may result in changes to the measurement of fair value. Generally, significant increases (decreases) in participant redemptions may result in measurements of significantly higher (lower) fair value of this liability.
Fair Values of Financial Instruments:
Estimates of fair value for financial instruments not carried at fair value on a recurring basis in our consolidated statement of condition, as defined by GAAP, are generally subjective in nature, and are made as of a specific point in time based on the characteristics of the financial instruments and relevant market information. Disclosure of fair-value estimates is not required by GAAP for certain items, such as lease financing, equity-method investments, obligations for pension and other post-retirement plans, premises and equipment, other intangible assets and income-tax assets and liabilities. Accordingly, aggregate fair-value estimates presented do not purport to represent, and should not be considered representative of, our underlying “market” or franchise value. In addition, because of potential differences in methodologies and assumptions used to estimate fair values, our estimates of fair value should not be compared to those of other financial institutions.
We use the following methods to estimate the fair values of our financial instruments:
•	For financial instruments that have quoted market prices, those quoted prices are used to estimate fair value.
•	For financial instruments that have no defined maturity, have a remaining maturity of 180 days or less, or reprice frequently to a market rate, we assume that the fair value of these instruments approximates their reported value, after taking into consideration any applicable credit risk.
•	For financial instruments for which no quoted market prices are available, fair value is estimated using information obtained from independent third parties, or by discounting the expected cash flows using an estimated current market interest rate for the financial instrument.
The generally short duration of certain of our assets and liabilities results in a significant number of financial instruments for which fair value equals or closely approximates the amount reported in our consolidated statement of condition. These financial instruments are reported in the following captions in our consolidated statement of condition: cash and due from banks; interest-bearing deposits with banks; securities purchased under resale agreements; accrued income receivable; deposits; securities sold under repurchase agreements; federal funds purchased; and other short-term borrowings.
In addition, due to the relatively short duration of certain of our net loans (excluding leases), we consider fair value for these loans to approximate their reported value. The fair value of other types of loans, such as senior secured bank loans, purchased receivables and commercial real estate loans, is estimated using information obtained from independent third parties or by discounting expected future cash flows using current rates at which similar loans would be made to borrowers with similar credit ratings for the same remaining maturities. Commitments to lend have no reported value because their terms are at prevailing market rates.
The following tables present the reported amounts and estimated fair values of the financial instruments defined by GAAP, excluding financial assets and liabilities carried at fair value on a recurring basis, as they would be categorized within the fair-value hierarchy, as of the dates indicated.
									Fair-Value Hierarchy
30-Sep-13		Reported Amount			Estimated Fair Value				Quoted Market Prices in Active Markets (Level 1)				Pricing Methods with Significant Observable Market Inputs (Level 2)			Pricing Methods with Significant Unobservable Market Inputs (Level 3)
(In millions)
Financial Assets:
Cash and due from banks		$	3,896		$	3,896			$	3,896			$	—		$	—
Interest-bearing deposits with banks		38,636			38,636				—				38,636			—
Securities purchased under resale agreements		5,827			5,827				—				5,827			—
Investment securities held to maturity		16,698			16,543				—				16,543			—
Loans (excluding leases)		14,445			14,431				—				13,968			463
Financial Liabilities:
Deposits:
Noninterest-bearing		$	45,679		$	45,679			$	—			$	45,679		$	—
Interest-bearing - U.S.		6,575			6,575				—				6,575			—
Interest-bearing - non-U.S.		101,945			101,945				—				101,945			—
Securities sold under repurchase agreements		10,123			10,123				—				10,123			—
Federal funds purchased		94			94				—				94			—
Other short-term borrowings		3,657			3,657				—				3,657			—
Long-term debt		8,748			9,101				—				8,125			976
									Fair-Value Hierarchy
31-Dec-12		Reported Amount			Estimated Fair Value				Quoted Market Prices in Active Markets (Level 1)				Pricing Methods with Significant Observable Market Inputs (Level 2)			Pricing Methods with Significant Unobservable Market Inputs (Level 3)
(In millions)
Financial Assets:
Cash and due from banks		$	2,590		$	2,590			$	2,590			$	—		$	—
Interest-bearing deposits with banks		50,763			50,763				—				50,763			—
Securities purchased under resale agreements		5,016			5,016				—				5,016			—
Investment securities held to maturity		11,379			11,661				—				11,661			—
Loans (excluding leases)		11,121			11,166				—				10,276			890
Financial Liabilities:
Deposits:
Noninterest-bearing		$	44,445		$	44,445			$	—			$	44,445		$	—
Interest-bearing - U.S.		19,201			19,201				—				19,201			—
Interest-bearing - non-U.S.		100,535			100,535				—				100,535			—
Securities sold under repurchase agreements		8,006			8,006				—				8,006			—
Federal funds purchased		399			399				—				399			—
Other short-term borrowings		4,502			4,502				—				4,502			—
Long-term debt		7,429			7,780				—				6,871			909

Investment_Securities

Investment Securities	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Investment Securities	'
	Investment Securities
	The following table presents the amortized cost and fair value, and associated unrealized gains and losses, of investment securities as of the dates indicated:
		September 30, 2013												December 31, 2012
		Amortized			Gross						Fair			Amortized		Gross				Fair
		Cost			Unrealized						Value			Cost		Unrealized				Value
	(In millions)				Gains			Losses								Gains		Losses
	Available for sale:
	U.S. Treasury and federal agencies:
	Direct obligations	$	729		$	11		$	2		$	738		$	823	$	19	$	1	$	841
	Mortgage-backed securities	24,562			275			262			24,575			31,640		598		26		32,212
	Asset-backed securities:
	Student loans(1)	15,079			94			302			14,871			16,829		100		508		16,421
	Credit cards	8,649			23			46			8,626			9,928		61		3		9,986
	Sub-prime	1,371			5			110			1,266			1,557		4		162		1,399
	Other	4,772			148			19			4,901			4,583		155		61		4,677
	Total asset-backed securities	29,871			270			477			29,664			32,897		320		734		32,483
	Non-U.S. debt securities:
	Mortgage-backed securities	10,773			241			13			11,001			11,119		313		27		11,405
	Asset-backed securities	5,445			25			3			5,467			6,180		42		4		6,218
	Government securities	3,537			4			—			3,541			3,197		2		—		3,199
	Other	4,556			58			14			4,600			4,221		86		1		4,306
	Total non-U.S. debt securities	24,311			328			30			24,609			24,717		443		32		25,128
	State and political subdivisions	9,307			171			180			9,298			7,384		234		67		7,551
	Collateralized mortgage obligations	5,152			79			73			5,158			4,818		151		15		4,954
	Other U.S. debt securities	4,925			153			33			5,045			5,072		233		7		5,298
	U.S. equity securities	34			5			—			39			28		3		—		31
	Non-U.S. equity securities	2			—			—			2			1		—		—		1
	U.S. money-market mutual funds	680			—			—			680			1,062		—		—		1,062
	Non-U.S. money-market mutual funds	174			—			—			174			121		—		—		121
	Total	$	99,747		$	1,292		$	1,057		$	99,982		$	108,563	$	2,001	$	882	$	109,682
	Held to maturity:
	U.S. Treasury and federal agencies:
	Direct obligations	$	5,003		$	—		$	390		$	4,613		$	5,000	$	—	$	8	$	4,992
	Mortgage-backed securities	100			7			—			107			153		11		—		164
	Asset-backed securities:
	Student loans(1)	1,502			—			11			1,491			—		—		—		—
	Credit cards	531			—			—			531			—		—		—		—
	Other	818			—			3			815			16		—		—		16
	Total asset-backed securities	2,851			—			14			2,837			16		—		—		16
	Non-U.S. debt securities:
	Mortgage-backed securities	4,109			130			67			4,172			3,122		85		68		3,139
	Asset-backed securities	1,486			18			2			1,502			434		16		1		449
	Government securities	16			—			—			16			3		—		—		3
	Other	190			—			—			190			167		—		2		165
	Total non-U.S. debt securities	5,801			148			69			5,880			3,726		101		71		3,756
	State and political subdivisions	61			1			—			62			74		2		—		76
	Collateralized mortgage obligations	2,882			193			31			3,044			2,410		259		12		2,657
	Total	$	16,698		$	349		$	504		$	16,543		$	11,379	$	373	$	91	$	11,661
	(1) Substantially composed of securities guaranteed by the federal government with respect to at least 97% of defaulted principal and
	accrued interest on the underlying loans.
	Aggregate investment securities carried at $48.28 billion and $46.66 billion as of September 30, 2013 and December 31, 2012, respectively, were designated as pledged for public and trust deposits, short-term borrowings and for other purposes as provided by law.
	The following tables present the aggregate fair values of investment securities that have been in a continuous unrealized loss position for less than 12 months, and those that have been in a continuous unrealized loss position for 12 months or longer, as of the dates indicated:
		Less than 12 months						12 months or longer						Total
	September 30, 2013	Fair			Gross			Fair			Gross			Fair		Gross
		Value			Unrealized			Value			Unrealized			Value		Unrealized
	(In millions)				Losses						Losses					Losses
	Available for sale:
	U.S. Treasury and federal agencies:
	Direct obligations	$	158		$	1		$	117		$	1		$	275	$	2
	Mortgage-backed securities	9,721			232			1,933			30			11,654		262
	Asset-backed securities:
	Student loans	2,123			19			7,463			283			9,586		302
	Credit cards	3,734			46			—			—			3,734		46
Sub-prime	16			1			1,193			109			1,209		110
Other	896			5			469			14			1,365		19
Total asset-backed securities	6,769			71			9,125			406			15,894		477
Non-U.S. debt securities:
Mortgage-backed securities	1,240			3			242			10			1,482		13
Asset-backed securities	708			1			21			2			729		3
Other	1,434			14			—			—			1,434		14
Total non-U.S. debt securities	3,382			18			263			12			3,645		30
State and political subdivisions	2,436			118			1,080			62			3,516		180
Collateralized mortgage obligations	1,665			65			304			8			1,969		73
Other U.S. debt securities	1,047			27			33			6			1,080		33
Total	$	25,178		$	532		$	12,855		$	525		$	38,033	$	1,057
Held to maturity:
U.S. Treasury and federal agencies:
Direct obligations	$	4,611		$	390		$	—		$	—		$	4,611	$	390
Asset-backed securities:
Student loans	1,234			11			—			—			1,234		11
Other	580			3			—			—			580		3
Total asset-backed securities	1,814			14			—			—			1,814		14
Non-U.S. debt securities:
Mortgage-backed securities	1,155			5			893			62			2,048		67
Asset-backed securities	717			2			—			—			717		2
Total non-U.S. debt securities	1,872			7			893			62			2,765		69
Collateralized mortgage obligations	905			27			96			4			1,001		31
Total	$	9,202		$	438		$	989		$	66		$	10,191	$	504
	Less than 12 months						12 months or longer						Total
December 31, 2012	Fair			Gross			Fair			Gross			Fair		Gross
	Value			Unrealized			Value			Unrealized			Value		Unrealized
(In millions)				Losses						Losses					Losses
Available for sale:
U.S. Treasury and federal agencies:
Direct obligations	$	—		$	—		$	132		$	1		$	132	$	1
Mortgage-backed securities	3,486			18			865			8			4,351		26
Asset-backed securities:
Student loans	625			6			10,241			502			10,866		508
Credit cards	888			3			—			—			888		3
Sub-prime	—			—			1,346			162			1,346		162
Other	639			13			989			48			1,628		61
Total asset-backed securities	2,152			22			12,576			712			14,728		734
Non-U.S. debt securities:
Mortgage-backed securities	670			3			453			24			1,123		27
Asset-backed securities	973			1			53			3			1,026		4
Other	509			1			—			—			509		1
Total non-U.S. debt securities	2,152			5			506			27			2,658		32
State and political subdivisions	685			9			1,152			58			1,837		67
Collateralized mortgage obligations	347			1			621			14			968		15
Other U.S. debt securities	302			1			33			6			335		7
Total	$	9,124		$	56		$	15,885		$	826		$	25,009	$	882
Held to maturity:
U.S. Treasury and federal agencies:
Direct obligations	$	3,792		$	8		$	—		$	—		$	3,792	$	8
Non-U.S. debt securities:
Mortgage-backed securities	56			1			956			67			1,012		68
Asset-backed securities	—			—			73			1			73		1
Other	—			—			156			2			156		2
Total non-U.S. debt securities	56			1			1,185			70			1,241		71
Collateralized mortgage obligations	120			1			153			11			273		12
Total	$	3,968		$	10		$	1,338		$	81		$	5,306	$	91
The following table presents contractual maturities of debt investment securities as of September 30, 2013:
(In millions)	Under 1			1 to 5			6 to 10			Over 10
	Year			Years			Years			Years
Available for sale:
U.S. Treasury and federal agencies:
Direct obligations	$	—		$	42		$	46		$	650
Mortgage-backed securities	103			1,847			6,188			16,437
Asset-backed securities:
Student loans	1,019			6,513			4,646			2,693
Credit cards	2,919			3,506			2,201			—
Sub-prime	26			28			2			1,210
Other	341			1,758			1,432			1,370
Total asset-backed securities	4,305			11,805			8,281			5,273
Non-U.S. debt securities:
Mortgage-backed securities	148			6,191			159			4,503
Asset-backed securities	253			4,685			378			151
Government securities	2,541			1,000			—			—
Other	1,143			2,912			545			—
Total non-U.S. debt securities	4,085			14,788			1,082			4,654
State and political subdivisions	668			3,059			3,565			2,006
Collateralized mortgage obligations	271			1,923			1,157			1,807
Other U.S. debt securities	215			4,094			703			33
Total	$	9,647		$	37,558		$	21,022		$	30,860
Held to maturity:
U.S. Treasury and federal agencies:
Direct obligations	$	—		$	—		$	5,000		$	3
Mortgage-backed securities	—			25			19			56
Asset-backed securities
Student loans	19			153			219			1,111
Credit cards	—			229			302			—
Other	—			510			302			6
Total asset-backed securities	19			892			823			1,117
Non-U.S. debt securities:
Mortgage-backed securities	—			939			164			3,006
Asset-backed securities	80			1,235			171			—
Government securities	16			—			—			—
Other	162			24			—			4
Total non-U.S. debt securities	258			2,198			335			3,010
State and political subdivisions	48			13			—			—
Collateralized mortgage obligations	102			1,174			502			1,104
Total	$	427		$	4,302		$	6,679		$	5,290
The maturities of asset-backed securities, mortgage-backed securities and collateralized mortgage obligations are based on expected principal payments.
The following table presents gross realized gains and gross realized losses from sales of available-for-sale securities and the components of net impairment losses, included in net gains and losses related to investment securities, for the periods indicated:
	Three Months Ended September 30,						Nine Months Ended September 30,
(In millions)	2013			2012			2013			2012
Gross realized gains from sales of available-for-sale securities	$	11		$	24		$	98		$	75
Gross realized losses from sales of available-for-sale securities(1)	(5		)	—			(87		)	(46		)
Gross losses from other-than-temporary impairment	(8		)	(4		)	(8		)	(50		)
Losses reclassified (from) to other comprehensive income	(2		)	(2		)	(12		)	23
Net impairment losses recognized in consolidated statement of income	(10		)	(6		)	(20		)	(27		)
Gains (losses) related to investment securities, net	$	(4	)	$	18		$	(9	)	$	2
Impairment associated with expected credit losses	$	(8	)	$	(1	)	$	(8	)	$	(14	)
Impairment associated with management's intent to sell impaired securities prior to recovery in value	—			—			(6		)	—
Impairment associated with adverse changes in timing of expected future cash flows	(2		)	(5		)	(6		)	(13		)
Net impairment losses recognized in consolidated statement of income	$	(10	)	$	(6	)	$	(20	)	$	(27	)
(1) Amount for the nine months ended September 30, 2012 represented a pre-tax loss from the sale of all of our Greek investment securities, which had an aggregate carrying value of approximately $91 million.
The following table presents activity with respect to net impairment losses for the periods indicated:
	Nine Months Ended September 30,
(In millions)	2013			2012
Beginning balance	$	124		$	113
Plus losses for which other-than-temporary impairment was not previously recognized	14			2
Plus losses for which other-than-temporary impairment was previously recognized	6			25
Less previously recognized losses related to securities sold or matured	(10		)	(21		)
Ending balance	$	134		$	119
Impairment:
We conduct periodic reviews of individual securities to assess whether other-than-temporary impairment exists. Impairment exists when the current fair value of an individual security is below its amortized cost basis. When the decline in the security's fair value is deemed to be other than temporary, the loss is recorded in our consolidated statement of income. In addition, for debt securities available for sale and held to maturity, impairment is recorded in our consolidated statement of income when management intends to sell (or may be required to sell) the securities before they recover in value, or when management expects the present value of cash flows expected to be collected from the securities to be less than the amortized cost of the impaired security (a credit loss).
Our review of impaired securities generally includes:
•	the identification and evaluation of securities that have indications of potential other-than-temporary impairment, such as issuer-specific concerns, including deteriorating financial condition or bankruptcy;
•	the analysis of expected future cash flows of securities, based on quantitative and qualitative factors;
•	the analysis of the collectibility of those future cash flows, including information about past events, current conditions and reasonable and supportable forecasts;
•	the analysis of the underlying collateral for mortgage- and asset-backed securities;
•	the analysis of individual impaired securities, including consideration of the length of time the security has been in an unrealized loss position, the anticipated recovery period, and the magnitude of the overall price decline;
•	discussion and evaluation of factors or triggers that could cause individual securities to be deemed other-than- temporarily impaired and those that would not support other-than-temporary impairment; and
•	documentation of the results of these analyses.
Factors considered in determining whether impairment is other than temporary include:
•	certain macroeconomic drivers;
•	certain industry-specific drivers;
•	the length of time the security has been impaired;
•	the severity of the impairment;
•	the cause of the impairment and the financial condition and near-term prospects of the issuer;
•	activity in the market with respect to the issuer's securities, which may indicate adverse credit conditions; and
•	our intention not to sell, and the likelihood that we will not be required to sell, the security for a period of time sufficient to allow for its recovery in value.
Substantially all of our investment securities portfolio is composed of debt securities. A critical component of our assessment of other-than-temporary impairment of these debt securities is the identification of credit-impaired securities for which management does not expect to receive cash flows sufficient to recover the entire amortized cost basis of the security.
Debt securities that are not deemed to be credit-impaired are subject to additional management analysis to assess whether management intends to sell, or, more likely than not, would be required to sell, the security before the expected recovery to its amortized cost basis.
The following describes our process for the identification and assessment of other-than-temporary impairment in security types with the most significant gross unrealized losses as of September 30, 2013.
U.S. Agency Residential Mortgage-Backed Securities
Our portfolio of U.S. agency residential mortgage-backed securities receives the implicit or explicit backing of the U.S. government in conjunction with specified financial support of the U.S. Treasury. No other-than-temporary impairment was recorded on these securities in the three and nine months ended September 30, 2013 or in the three and nine months ended September 30, 2012. The unrealized losses on these securities as of September 30, 2013 were primarily attributable to changes in interest rates in 2013.
Asset-Backed Securities - Student Loans
Asset-backed securities collateralized by student loans are primarily composed of securities collateralized by Federal Family Education Loan Program, or FFELP, loans. FFELP loans benefit from a federal government guarantee of at least 97% of defaulted principal and accrued interest, with additional credit support provided in the form of over-collateralization, subordination and excess spread, which collectively total in excess of 100%. Accordingly, the vast majority of FFELP loan-backed securities are protected from traditional consumer credit risk.
We recorded no other-than-temporary impairment on these securities in the three and nine months ended September 30, 2013 or the three and nine months ended September 30, 2012. The gross unrealized losses in our FFELP loan-backed securities portfolio as of September 30, 2013 were primarily attributable to lower liquidity and the lower spreads on these securities relative to those associated with more current issuances. Our assessment of other-than-temporary impairment of these securities considers, among many other factors, the strength of the U.S. government guarantee, the performance of the underlying collateral, and the remaining average term of the FFELP loan-backed securities portfolio, which was approximately 5.0 years as of September 30, 2013. In addition, our total exposure to private student loan-backed securities was less than $900 million as of September 30, 2013. Our assessment of other-than-temporary impairment of private student loan-backed securities considers, among other factors, the impact of high unemployment rates on the collateral performance of private student loans.
Non-U.S. Mortgage- and Asset-Backed Securities
Non-U.S. mortgage- and asset-backed securities are primarily composed of U.K., Australian and Dutch securities collateralized by residential mortgages and German securities collateralized by auto loans and leases. Our assessment of impairment considers the location of the underlying collateral, collateral enhancement and structural features, expected credit losses under base-case and stressed conditions and the macroeconomic outlook for the country in which the collateral is located, including housing prices and unemployment. Where appropriate, any potential loss after consideration of the above-referenced factors is further evaluated to determine whether any other-than-temporary impairment exists.
In the three and nine months ended September 30, 2013, we recorded other-than-temporary impairment of $2 million and $6 million, respectively, on certain of our non-U.S. mortgage-backed securities, the result of adverse changes in the timing of expected future cash flows from the securities, in our consolidated statement of income. In addition, in the nine months ended September 30, 2013, we recorded other-than-temporary impairment of $6 million, all in the three months ended June 30, 2013, on one of these securities, associated with management's intent to sell the impaired security prior to its recovery in value.
In the three months ended September 30, 2012, we recorded other-than-temporary impairment of $5 million, substantially related to non-U.S. mortgage-backed securities, the result of adverse changes in the timing of expected future cash flows from the securities, in our consolidated statement of income. In the nine months ended September 30, 2012, we recorded other-than-temporary impairment of $19 million, substantially related to non-U.S. mortgage-backed securities, of which $6 million was associated with expected credit losses and $13 million resulted from adverse changes in the timing of expected future cash flows from the securities.
Our aggregate exposure to Spain, Italy, Ireland and Portugal totaled approximately $570 million as of September 30, 2013. We had no direct sovereign debt exposure to any of these countries as of that date, but we had indirect exposure consisting of mortgage- and asset-backed securities, composed of $269 million in Spain, $106 million in Italy, $118 million in Ireland and $77 million in Portugal. As of September 30, 2013, these securities had an aggregate pre-tax net unrealized gain of approximately $39 million, composed of gross unrealized gains of $63 million and gross unrealized losses of $24 million.
We recorded no other-than-temporary impairment on any of these securities in the three months ended September 30, 2013. We recorded the above-described other-than-temporary impairment of $6 million on one of these securities in the nine months ended September 30, 2013, all in the three months ended June 30, 2013, associated with management's intent to sell the impaired security prior to its recovery in value. We recorded no other-than-temporary impairment in the three months ended September 30, 2012. We recorded the above-mentioned other-than-temporary impairment of $6 million on certain of these securities in the nine months ended September 30, 2012, all in the three months ended June 30, 2012, associated with expected credit losses.
Our assessment of other-than-temporary impairment of these securities takes into account government intervention in the corresponding mortgage markets and assumes a negative baseline macroeconomic environment for this region, due to a combination of slower economic growth and continued government austerity measures. Our baseline view assumes a recessionary period characterized by high unemployment and by additional housing price declines of between 10% and 18% across these four countries. Our evaluation of other-than-temporary impairment in our base case does not assume a disorderly sovereign-debt restructuring or a break-up of the Eurozone. In addition, stress testing and sensitivity analysis is performed in order to understand the impact of more severe assumptions on potential other-than-temporary impairment.
State and Political Subdivisions and Other U.S. Debt Securities
Our municipal securities portfolio primarily includes securities issued by U.S. states and their municipalities. A portion of this portfolio is held in connection with our tax-exempt investment program, more fully described in note 9. Our other U.S. debt securities portfolio is primarily composed of securities issued by U.S. corporations.  The gross unrealized losses in each portfolio as of September 30, 2013 were primarily attributable to fluctuations in interest rates in 2013.
Our assessment of other-than-temporary impairment of these portfolios considers, among other factors, adverse conditions specifically related to the industry, geographic area or financial condition of the issuer; the structure of the security, including collateral, if any, and payment schedule; rating agency changes to the security's credit rating; the volatility of the fair value changes; and our intent and ability to hold the security until its recovery in value.  If the impairment of the security is credit-related, we estimate the future cash flows from the security, tailored to the security and considering the above-described factors, and any resulting other-than-temporary impairment is recorded in our consolidated statement of income.  We recorded no other-than-temporary impairment on these securities in the three and nine months ended September 30, 2013 and the three and nine months ended September 30, 2012.
U.S. Non-Agency Residential Mortgage-Backed Securities
For U.S. non-agency residential mortgage-backed securities, we assess other-than-temporary impairment using cash-flow models, tailored for each security, that estimate the future cash flows from the underlying mortgages, using the security-specific collateral and transaction structure. Estimates of future cash flows are subject to management judgment. The future cash flows and performance of our portfolio of U.S. mortgage-backed securities are a function of a number of factors, including, but not limited to, the condition of the U.S. economy, the condition of the U.S. residential mortgage markets, and the level of loan defaults, prepayments and loss severities. Management's estimates of future losses for each security also consider the underwriting and historical performance of each specific security, the underlying collateral type, vintage, borrower profile, third-party guarantees, current levels of subordination, geography and other factors.
No other-than-temporary impairment was recorded on these securities in the three and nine months ended September 30, 2013. We recorded other-than-temporary impairment of $1 million and $8 million on these securities, all associated with expected credit losses, in our consolidated statement of income in the three and nine months ended September 30, 2012, respectively.
Collateralized Mortgage Obligations
For U.S. commercial mortgage-backed securities, other-than-temporary impairment is assessed by considering a number of factors, including, but not limited to, the condition of the U.S. economy and the condition of the U.S. commercial real estate market, as well as capitalization rates. Management estimates of future losses for each security also consider the underlying collateral type, property location, vintage, debt-service coverage ratios, expected property income, servicer advances and estimated property values, as well as current levels of subordination. We recorded $8 million of other-than-temporary impairment on these securities, all associated with expected credit losses, in our consolidated statement of income in both the three and nine months ended September 30, 2013. No other-than-temporary impairment was recorded on these securities in the three and nine months ended September 30, 2012.
*****
The estimates, assumptions and other risk factors utilized in our assessment of impairment as described above are used by management to identify securities which are subject to further analysis of potential credit losses. Additional analyses are performed using more stressful assumptions to further evaluate the sensitivity of losses relative to the above-described factors. However, since the assumptions are based on the unique characteristics of each security, management uses a range of estimates for prepayment speeds, default, and loss severity forecasts that reflect the collateral profile of the securities within each asset class. In addition, in measuring expected credit losses, the individual characteristics of each security are examined to determine whether any additional factors would increase or mitigate the expected loss. Once losses are determined, the timing of the loss will also affect the ultimate other-than-temporary impairment, since the loss is ultimately subject to a discount commensurate with the purchase yield of the security.
In the aggregate, we recorded other-than-temporary impairment of $10 million and $20 million in the three and nine months ended September 30, 2013, respectively, compared to $6 million and $27 million in the three and nine months ended September 30, 2012, respectively. Of the $10 million recorded in the three months ended September 30, 2013, $8 million was associated with expected credit losses and $2 million resulted from adverse changes in the timing of expected future cash flows from the securities. Of the $20 million recorded in the nine months ended September 30, 2013, $8 million was associated with expected credit losses, $6 million resulted from management's intent to sell an impaired security prior to its recovery in value, and $6 million resulted from adverse changes in the timing of expected future cash flows from the securities. Of the $6 million and $27 million recorded in the three and nine months ended September 30, 2012, $1 million and $14 million, respectively, was associated with expected credit losses, and $5 million and $13 million, respectively, resulted from adverse changes in the timing of expected future cash flows from the securities.
After a review of the investment portfolio, taking into consideration current economic conditions, adverse situations that might affect our ability to fully collect principal and interest, the timing of future payments, the credit quality and performance of the collateral underlying mortgage- and asset-backed securities and other relevant factors, and excluding other-than-temporary impairment recorded in the nine months ended September 30, 2013, management considers the aggregate decline in fair value of the investment securities portfolio and the resulting gross pre-tax unrealized losses of $1.56 billion related to 2,607 securities as of September 30, 2013 to be temporary, and not the result of any material changes in the credit characteristics of the securities.

Loans_and_Leases

Loans and Leases	9 Months Ended
	Sep. 30, 2013
Loans and Leases Receivable Disclosure [Abstract]	'
Loans and Leases	'
	Loans and Leases
	The following table presents our recorded investment in loans and leases, by segment and class, as of the dates indicated:
	(In millions)	September 30, 2013			December 31, 2012
	Institutional:
	Investment funds:
	U.S.	$	10,017		$	8,376
	Non-U.S.	1,998			829
	Commercial and financial:
	U.S.	1,486			613
	Non-U.S.	509			520
	Purchased receivables:
	U.S.	231			276
	Non-U.S.	60			118
	Lease financing:
	U.S.	357			380
	Non-U.S.	754			784
	Total institutional	15,412			11,896
	Commercial real estate:
	U.S.	166			411
	Total loans and leases	15,578			12,307
	Allowance for loan losses	(22		)	(22		)
	Loans and leases, net of allowance for loan losses	$	15,556		$	12,285
	The commercial-and-financial class in the institutional segment presented in the table above included approximately $375 million of senior secured bank loans as of September 30, 2013. We had no investment in senior secured bank loans as of December 31, 2012. These loans resulted from our participation in loan syndications in the non-investment-grade lending market in the three months ended September 30, 2013. These commercial-and-financial loans are included in the "speculative" category in the credit-quality-indicator table below as of September 30, 2013.
	These loans present more significant exposure to potential credit losses. However, we seek to mitigate such exposure, in part through the limitation of our investment to larger, more liquid credits underwritten by major global financial institutions, the application of our internal credit analysis process to each potential investment, and diversification by counterparty and industry segment. As of September 30, 2013, we had no allowance for loan losses with respect to these commercial-and-financial loans.
	Aggregate short-duration advances to our clients included in the investment-funds and commercial-and-financial classes in the institutional segment were $4.65 billion and $3.30 billion as of September 30, 2013 and December 31, 2012, respectively.
	The following tables present our recorded investment in each class of loans and leases by credit quality indicator as of the dates indicated:
		Institutional										Commercial Real Estate
	September 30, 2013	Investment			Commercial and Financial			Purchased		Lease		Property Development			Other			Total
		Funds						Receivables		Financing								Loans and
	(In millions)																	Leases
	Investment grade(1)	$	11,574		$	1,456		$	291	$	1,079	$	—		$	29		$	14,429
	Speculative(2)	441			519			—		32		137			—			1,129
	Special mention(3)	—			20			—		—		—			—			20
	Total	$	12,015		$	1,995		$	291	$	1,111	$	137		$	29		$	15,578
		Institutional										Commercial Real Estate
	December 31, 2012	Investment			Commercial and Financial			Purchased		Lease		Property Development			Other			Total
		Funds						Receivables		Financing								Loans and
	(In millions)																	Leases
	Investment grade(1)	$	8,937		$	1,041		$	394	$	1,137	$	—		$	29		$	11,538
	Speculative(2)	268			92			—		27		377			5			769
	Total	$	9,205		$	1,133		$	394	$	1,164	$	377		$	34		$	12,307
	( 1) Investment grade loans and leases consist of counterparties with strong credit quality and low expected credit risk and probability of default. Ratings apply to counterparties with a strong capacity to support the timely repayment of any financial commitment.
	(2) Speculative loans and leases consist of counterparties that face ongoing uncertainties or exposure to business, financial, or economic downturns. However, these counterparties may have financial flexibility or access to financial alternatives, which allow for financial commitments to be met.
	(3) Special mention loans and leases consist of counterparties with potential weaknesses that, if uncorrected, may result in deterioration of repayment prospects.
	Loans and leases are categorized in the rating categories presented in the table above that align with our internal risk-rating framework. Management considers the ratings to be current as of September 30, 2013. We use an internal risk-rating system to assess our risk of credit loss for each loan or lease. This risk-rating process incorporates the use of risk-rating tools in conjunction with management judgment. Qualitative and quantitative inputs are captured in a systematic manner, and following a formal review and approval process, an internal credit rating based on our credit scale is assigned.
	In assessing the risk rating assigned to each individual loan or lease, among the factors considered are the borrower's debt capacity, collateral coverage, payment history and delinquency experience, financial flexibility and earnings strength, the expected amounts and sources of repayment, the level and nature of contingencies, if any, and the industry and geography in which the borrower operates. These factors are based on an evaluation of historical and current information, and involve subjective assessment and interpretation. Credit counterparties are evaluated and risk-rated on an individual basis at least annually.
	The following table presents our recorded investment in loans and leases, disaggregated based on our impairment methodology, as of the dates indicated:
		September 30, 2013								December 31, 2012
	(In millions)	Institutional			Commercial Real Estate			Total Loans and Leases		Institutional		Commercial Real Estate			Total Loans and Leases
	Loans and leases:
	Individually evaluated for impairment	$	405		$	137		$	542	$	11	$	411		$	422
	Collectively evaluated for impairment(1)	15,007			29			15,036		11,885		—			11,885
	Total	$	15,412		$	166		$	15,578	$	11,896	$	411		$	12,307
	(1) As of both September 30, 2013 and December 31, 2012, the entire $22 million allowance for loan losses was related to institutional loans collectively evaluated for impairment.
	The following tables present information related to our recorded investment in impaired loans and leases as of the dates, or for the periods, indicated:
		September 30, 2013								December 31, 2012
	(In millions)	Recorded Investment			Unpaid			Related Allowance(1)		Recorded Investment		Unpaid			Related Allowance(1)
					Principal							Principal
					Balance							Balance
	With no related allowance recorded:
	CRE—property development	$	130		$	143		$	—	$	197	$	224		$	—
	CRE—property development—acquired credit-impaired	—			34			—		—		34			—
	CRE—other—acquired credit-impaired	—			21			—		—		64			—
Total CRE	$	130		$	198		$	—	$	197	$	322		$	—
(1) As of both September 30, 2013 and December 31, 2012, we maintained an allowance for loan losses of $22 million associated with loans and leases that were not impaired.
	Three Months Ended September 30,										Nine Months Ended September 30,
	Average Recorded Investment						Interest Revenue Recognized				Average Recorded Investment						Interest Revenue Recognized
(In millions)	2013			2012			2013		2012		2013			2012			2013		2012
With no related allowance recorded:
CRE—property development	$	130		$	199		$	2	$	4	$	160		$	199		$	17	$	12
CRE—other—acquired credit-impaired	—			5			—		—		—			17			—		—
With an allowance recorded:
CRE—other—acquired credit-impaired	—			—			—		—		—			—			—		—
Total CRE	$	130		$	204		$	2	$	4	$	160		$	216		$	17	$	12
As of September 30, 2013 and December 31, 2012, we held an aggregate of approximately $130 million and $197 million, respectively, of commercial real estate, or CRE, loans which were modified in troubled debt restructurings. No impairment loss was recognized upon restructuring of the loans, as the discounted cash flows of the modified loans exceeded the carrying amount of the original loans as of the modification date. During the nine months ended September 30, 2013 and the year ended December 31, 2012, no loans were modified in troubled debt restructurings.
The following table presents activity in the allowance for loan losses for the periods indicated:
	Three Months Ended September 30,
	2013								2012
(In millions)	Institutional			Commercial			Total Loans and Leases		Institutional		Commercial			Total Loans
				Real Estate							Real Estate			and Leases
Allowance for loan losses:
Beginning balance	$	22		$	—		$	22	$	22	$	—		$	22
Provisions	—			—			—		—		—			—
Recoveries	—			—			—		—		—			—
Ending balance	$	22		$	—		$	22	$	22	$	—		$	22
	Nine Months Ended September 30,
	2013								2012
(In millions)	Institutional			Commercial			Total Loans and Leases		Institutional		Commercial			Total Loans
				Real Estate							Real Estate			and Leases
Allowance for loan losses:
Beginning balance	$	22		$	—		$	22	$	22	$	—		$	22
Provisions	—			—			—		—		(1		)	(1		)
Recoveries	—			—			—		—		1			1
Ending balance	$	22		$	—		$	22	$	22	$	—		$	22
Loans and leases are reviewed on a regular basis, and any provisions for loan losses that are recorded reflect management's estimate of the amount necessary to maintain the allowance for loan losses at a level considered appropriate to absorb estimated incurred losses in the loan-and-lease portfolio.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Other Intangible Assets	'
	Goodwill and Other Intangible Assets
	The following table presents changes in the carrying amount of goodwill during the periods indicated:
		Nine Months Ended September 30,
		2013									2012
	(In millions)	Investment			Investment			Total			Investment			Investment			Total
		Servicing			Management						Servicing			Management
	Beginning balance	$	5,941		$	36		$	5,977		$	5,610		$	35		$	5,645
	Divestitures	(7		)	—			(7		)	—			—			—
	Foreign currency translation, net	35			1			36			5			—			5
	Ending balance	$	5,969		$	37		$	6,006		$	5,615		$	35		$	5,650
	The following table presents changes in the net carrying amount of other intangible assets during the periods indicated:
		Nine Months Ended September 30,
		2013									2012
	(In millions)	Investment			Investment			Total			Investment			Investment			Total
		Servicing			Management						Servicing			Management
	Beginning balance	$	2,492		$	47		$	2,539		$	2,408		$	51		$	2,459
	Divestitures	(5		)	—			(5		)	—			—			—
	Amortization	(153		)	(7		)	(160		)	(143		)	(2		)	(145		)
	Foreign currency translation, net	22			—			22			(3		)	—			(3		)
	Ending balance	$	2,356		$	40		$	2,396		$	2,262		$	49		$	2,311
	The following table presents the gross carrying amount, accumulated amortization and net carrying amount of other intangible assets by type as of the dates indicated:
		September 30, 2013									December 31, 2012
	(In millions)	Gross			Accumulated			Net			Gross			Accumulated			Net
		Carrying			Amortization			Carrying			Carrying			Amortization			Carrying
		Amount						Amount			Amount						Amount
	Client relationships	$	2,669		$	(917	)	$	1,752		$	2,653		$	(755	)	$	1,898
	Core deposits	712			(180		)	532			706			(192		)	514
	Other	248			(136		)	112			244			(117		)	127
	Total	$	3,629		$	(1,233	)	$	2,396		$	3,603		$	(1,064	)	$	2,539

Other_Assets_and_Other_Liabili

Other Assets and Other Liabilities	9 Months Ended
	Sep. 30, 2013
Other Assets [Abstract]	'
Other Assets and Other Liabilities	'
	Other Assets and Other Liabilities
	Other Assets:
	The following table presents the components of other assets as of the dates indicated:
	(In millions)	September 30, 2013		December 31, 2012
	Collateral deposits, net	$	12,106	$	7,649
	Unrealized gains on derivative financial instruments, net	4,320		4,556
	Bank-owned life insurance	2,027		2,000
	Investments in joint ventures and other unconsolidated entities	1,466		1,405
	Accounts receivable	1,109		511
	Receivable for securities settlement	358		33
	Deferred tax assets, net of valuation allowance	302		353
	Prepaid expenses	299		267
	Income taxes receivable	261		252
	Deposits with clearing organizations	179		174
	Receivable for securities sold	92		1
	Other(1)	838		815
	Total	$	23,357	$	18,016
	(1)	Included other real estate owned of approximately $58 million and $65 million, respectively.
	Accrued Expenses and Other Liabilities:
	Accrued expenses and other liabilities as of September 30, 2013 and December 31, 2012 included $6.39 billion and $4.99 billion, respectively, of collateral received from clients in connection with our participation in principal securities finance transactions.

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2013
Long-term Debt, Unclassified [Abstract]	'
Long-Term Debt	'
	Long-Term Debt
	In May 2013, we issued an aggregate of $1.50 billion of long-term debt, composed of $500 million of 1.35% senior notes due May 15, 2018 and $1.0 billion of 3.1% subordinated notes due May 15, 2023. Interest on the 1.35% senior notes and the 3.1% subordinated notes is payable semi-annually in arrears on May 15 and November 15 of each year, beginning on November 15, 2013. The 3.1% subordinated notes qualify for inclusion in tier 2 regulatory capital under federal regulatory capital guidelines.

Commitments_Guarantees_and_Con

Commitments, Guarantees, and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments, Guarantees, and Contingencies	'
	Commitments, Guarantees and Contingencies
	Commitments:
	We had unfunded off-balance sheet commitments to extend credit totaling $19.98 billion and $17.86 billion as of September 30, 2013 and December 31, 2012, respectively. The potential losses associated with these commitments equal the gross contractual amounts, and do not consider the value of any collateral. Approximately 75% of our unfunded commitments to extend credit expire within one year from the date of issue. Since many of these commitments are expected to expire or renew without being drawn upon, the gross contractual amounts do not necessarily represent our future cash requirements.
	Guarantees:
	Off-balance sheet guarantees are composed of indemnified securities financing, stable value protection, unfunded commitments to purchase assets, and standby letters of credit. The potential losses associated with these guarantees equal the gross contractual amounts, and do not consider the value of any collateral. The following table presents the aggregate gross contractual amounts of off-balance sheet guarantees as of the dates indicated. Amounts presented do not reflect participations to independent third parties.
	(In millions)	September 30, 2013		December 31, 2012
	Indemnified securities financing	$	315,632	$	302,341
	Stable value protection	27,913		33,512
	Asset purchase agreements	4,646		5,063
	Standby letters of credit	4,601		4,552
	Indemnified Securities Financing
	On behalf of our clients, we lend their securities, as agent, to brokers and other institutions. In most circumstances, we indemnify our clients for the fair market value of those securities against a failure of the borrower to return such securities. We require the borrowers to maintain collateral in an amount equal to or in excess of 100% of the fair market value of the securities borrowed. Securities on loan are revalued daily to determine if additional collateral is necessary. Collateral received in connection with our securities lending services is held by us as agent and is not recorded in our consolidated statement of condition.
	The cash collateral held by us as agent is invested on behalf of our clients. In certain cases, the cash collateral is invested in third-party repurchase agreements, for which we indemnify the client against loss of the principal invested. We require the counterparty to the indemnified repurchase agreement to provide collateral in an amount equal to or in excess of 100% of the amount of the repurchase agreement. In our role as agent, the indemnified repurchase agreements and the related collateral held by us are not recorded in our consolidated statement of condition.
	The following table summarizes the fair values of indemnified securities financing and related collateral, as well as collateral invested in indemnified repurchase agreements, as of the dates indicated:
	(In millions)	September 30, 2013		December 31, 2012
	Aggregate fair value of indemnified securities financing	$	315,632	$	302,341
	Aggregate fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing	327,567		312,223
	Aggregate fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements	86,461		80,224
	Aggregate fair value of cash and securities held by us or our agents as collateral for investments in indemnified repurchase agreements	91,884		85,411
	In certain cases, we participate in securities finance transactions as a principal. As principal, we borrow securities from the lending client and then lend such securities to the subsequent borrower, either a State Street client or a broker/dealer. Collateral provided and received in connection with such transactions is recorded in other assets and accrued expenses and other liabilities, respectively, in our consolidated statement of condition. As of September 30, 2013 and December 31, 2012, we had approximately $9.76 billion and $6.83 billion, respectively, of collateral provided and approximately $6.39 billion and $4.99 billion, respectively, of collateral received from clients in connection with our participation in principal securities finance transactions.
	Stable Value Protection
	In the normal course of our business, we offer products that provide book-value protection, primarily to plan participants in stable value funds managed by non-affiliated investment managers of post-retirement defined contribution benefit plans, particularly 401(k) plans. The book-value protection is provided on portfolios of intermediate, investment grade fixed-income securities, and is intended to provide safety and stable growth of principal invested. The protection is intended to cover any shortfall in the event that a significant number of plan participants withdraw funds when book value exceeds market value and the liquidation of the assets is not sufficient to redeem the participants. The investment parameters of the underlying portfolios, combined with structural protections, are designed to provide cushion and guard against payments even under extreme stress scenarios.
	These contingencies are individually accounted for as derivative financial instruments. The notional amounts of these contingencies are presented as “derivatives not designated as hedging instruments” in the table of aggregate notional amounts of derivative financial instruments provided in note 11. As of September 30, 2013, we have not made a payment under these contingencies that we consider material to our consolidated financial condition, and management believes that the probability of payment under these contingencies in the future, that we would consider material to our consolidated financial condition, is remote.
	Contingencies:
	Legal Proceedings
	In the ordinary course of business, we and our subsidiaries are involved in disputes, litigation and regulatory inquiries and investigations, both pending and threatened. These matters, if resolved adversely against us, may result in monetary damages, fines and penalties or require changes in our business practices. The resolution of these matters is inherently difficult to predict. Based on our assessment of these pending matters, we do not believe that the amount of any judgment, settlement or other action arising from any pending matter is likely to have a material adverse effect on our consolidated financial condition.  However, an adverse outcome in certain of the matters described below could have a material adverse effect on our consolidated results of operations for the period in which such matter is resolved or a reserve is determined to be required, on our consolidated financial condition or on our reputation.
	We evaluate our needs for accruals of loss contingencies related to legal proceedings on a case-by-case basis. When we have a liability that we deem probable and can be reasonably estimated as of the date of our consolidated financial statements, we accrue for our estimate of the loss. We may also establish a reserve if we determine that the cost of litigation can be avoided through a settlement. Once established, a reserve is subject to subsequent adjustment as a result of additional information. The resolution of proceedings and a range of reasonably estimable loss are inherently difficult to predict, especially in the early stages of proceedings. Even if a loss is probable, due to many complex factors, such as speed of discovery and the timing of court decisions or rulings, a range of loss might not be reasonably estimated until the later stages of the proceeding.
	To the extent that we have established reserves in our consolidated statement of condition for probable loss contingencies, such reserves may not be sufficient to cover our ultimate financial exposure associated with any settlements or judgments. We may be subject to proceedings in the future that, if adversely resolved, would have a material adverse effect on our businesses or on our future consolidated financial statements. Except where otherwise noted below, we have not established reserves with respect to the claims discussed and do not believe that potential exposure is either probable or can be reasonably estimated.
	SSgA
	We are currently defending two related ERISA class actions by investors in unregistered SSgA-managed collective trust funds and common trust funds which challenge the division of our securities lending-related revenue between those funds and State Street in its role as lending agent. The first action alleges, among other things, that State Street breached its fiduciary duty to investors in those funds. The plaintiff contends that other State Street agency lending clients received more favorable fee splits than did the SSgA lending funds. In August 2012, the Court certified a class consisting of ERISA plans that invested in SSgA collective trust funds between April 2004 and the present. The plaintiff alleges that class members paid between $145 million and $237 million in excess fees during the class period. The second action, filed in January 2013, challenges the division of our securities lending-related revenue between common trust funds and State Street in its role as lending agent. It alleges, among other things, that State Street breached its fiduciary duty under ERISA and state common law to investors in those funds. We have established a reserve of $15 million in connection with these matters.
	Securities Finance
	Two related participants in our agency securities lending program have brought suit against us challenging actions taken by us in response to their withdrawal from the program. We believe that certain withdrawals by these participants were inconsistent with the redemption policy applicable to the agency lending collateral pools and, consequently, redeemed their remaining interests through an in-kind distribution that reflected the assets these participants would have received had they acted in accordance with the collateral pools' redemption policy. In taking these actions, we believe that we acted in the best interests of all participants in the collateral pools. The two participants have asserted damages of $120 million, an amount that plaintiffs have stated was the difference between the amortized cost and market value of the assets that State Street proposed to distribute to the plans in-kind on or about August 2009. While management does not believe that such difference is an appropriate measure of damages, as of September 30, 2010, the last date on which State Street acted as custodian for the participants, the difference between the amortized cost and market value of the in-kind distribution was approximately $49 million. We have been informed that the participants liquidated these securities in June 2013, and that the realized loss on those sales was approximately $11.3 million. We have established a reserve of $10 million in connection with this matter.
	Foreign Exchange
	We offer our custody clients and their investment managers the option to route foreign exchange transactions to our foreign exchange desk through our asset servicing operation. We record as revenue an amount approximately equal to the difference between the rates we set for those trades and indicative interbank market rates at the time of settlement of the trade. As discussed more fully below, claims have been asserted on behalf of certain current and former custody clients, and future claims may be asserted, alleging that our indirect foreign exchange rates (including the differences between those rates and indicative interbank market rates at the time we executed the trades) were not adequately disclosed or were otherwise improper, and seeking to recover, among other things, the full amount of the revenue we obtained from our indirect foreign exchange trading with them.
	In October 2009, the Attorney General of the State of California commenced an action under the California False Claims Act and California Business and Professional Code related to services State Street provides to California state pension plans. The California Attorney General asserts that the pricing of certain foreign exchange transactions for these pension plans was governed by the custody contracts for these plans and that our pricing was not consistent with the terms of those contracts and related disclosures to the plans, and that, as a result, State Street made false claims and engaged in unfair competition. The Attorney General asserts actual damages of approximately $100 million for periods from 2001 to 2009 and seeks additional penalties, including treble damages. This action is in the discovery phase.
	In October 2010, we entered into a $12 million settlement with the State of Washington. This settlement resolves a contract dispute related to the manner in which we priced some foreign exchange transactions during our ten-year relationship with the State of Washington. Our contractual obligations and related disclosures to the State of Washington were significantly different from those presented in our ongoing litigation in California.
	We provide custody and principal foreign exchange services to government pension plans in other jurisdictions. Since the commencement of the litigation in California, attorneys general and other governmental authorities from a number of jurisdictions, as well as U.S. Attorney's offices, the U.S. Department of Labor and the SEC, have requested information or issued subpoenas in connection with inquiries into the pricing of our foreign exchange services. We continue to respond to such inquiries and subpoenas.
	We offer indirect foreign exchange services such as those we offer to the California pension plans to a broad range of custody clients in the U.S. and internationally. We have responded and are responding to information requests from a number of clients concerning our indirect foreign exchange rates. In February 2011, a putative class action was filed in federal court in Boston seeking unspecified damages, including treble damages, on behalf of all custodial clients that executed certain foreign exchange transactions with State Street from 1998 to 2009. The putative class action alleges, among other things, that the rates at which State Street executed foreign currency trades constituted an unfair and deceptive practice under Massachusetts law and a breach of the duty of loyalty.
	Two other putative class actions are currently pending in federal court in Boston alleging various violations of ERISA on behalf of all ERISA plans custodied with us that executed indirect foreign exchange transactions with State Street from 1998 onward. The complaints allege that State Street caused class members to pay unfair and unreasonable rates for indirect foreign exchange transactions with State Street. The complaints seek unspecified damages, disgorgement of profits, and other equitable relief.
	We have not established a reserve with respect to any of the pending legal proceedings related to our indirect foreign exchange services. We cannot provide any assurance as to the outcome of the pending proceedings, or whether other proceedings might be commenced against us by clients or government authorities. We expect that plaintiffs will seek to recover their share of all or a portion of the revenue that we have recorded from providing indirect foreign exchange services.
	Our estimated total revenue worldwide from such services was approximately $223 million for the nine months ended September 30, 2013, approximately $248 million for the year ended December 31, 2012, approximately $331 million for the year ended December 31, 2011, approximately $336 million for the year ended December 31, 2010, approximately $369 million for the year ended December 31, 2009 and approximately $462 million for the year ended December 31, 2008. Although we did not calculate revenue for such services prior to 2006 in the same manner, and have refined our calculation method over time, we believe that the amount of our revenue for such services has been of a similar or lesser order of magnitude for many years. Our revenue calculations related to indirect foreign exchange services reflect a judgment concerning the relationship between the rates we charge for indirect foreign exchange execution and indicative interbank market rates near in time to execution. Our revenue from foreign exchange trading generally depends on the difference between the rates we set for indirect trades and indicative interbank market rates on the date trades settle.
	We cannot predict the outcome of any pending matters or whether a court, in the event of an adverse resolution, would consider our revenue to be the appropriate measure of damages.
	Shareholder Litigation
	Three shareholder-related complaints are currently pending in federal court in Boston. One complaint purports to be a class action on behalf of State Street shareholders. The two other complaints purport to be class actions on behalf of participants and beneficiaries in the State Street Salary Savings Program who invested in the program's State Street common stock investment option. The complaints variously allege violations of the federal securities laws, common law and ERISA in connection with our foreign exchange trading business, our investment securities portfolio and our asset-backed commercial paper conduit program. A fourth complaint, a purported shareholder derivative action on behalf of State Street, was dismissed in September 2013. We have not established a reserve with respect to these matters.
	Transition Management
	In 2011, we identified a limited number of instances in which clients of our U.K. transition management businesses had been intentionally charged amounts in excess of the contractual terms. We conducted an investigation of such business with the assistance of external counsel and accounting firms; we notified and have reimbursed the limited number of clients which we identified as having been intentionally overcharged. We also reported this matter to the U.K. Financial Conduct Authority, or FCA, and are cooperating with them and the SEC in connection with this matter. We have established reserves in an aggregate amount of $13.4 million for indemnification costs and the potential for a financial penalty in connection with a resolution of this matter with the FCA.
	Investment Servicing
	State Street is named as a defendant in a series of related complaints by investment management clients of TAG Virgin Islands, Inc., or TAG, who hold or held custodial accounts with State Street. The complaints, collectively, allege various claims in connection with certain assets managed by TAG and custodied with State Street. We established a reserve of $9 million in the three months ended June 30, 2013 in connection with these matters. During the three months ended September 30, 2013, we entered into settlements with certain of the plaintiffs and had a remaining reserve of $6.5 million as of September 30, 2013.
	Income Taxes
	In the normal course of our business, we are subject to challenges from U.S. and non-U.S. income tax authorities regarding the amount of income taxes due. These challenges may result in adjustments to the timing or amount of taxable income or deductions or the allocation of taxable income among tax jurisdictions. Unrecognized tax benefits totaled approximately $116 million and $95 million as of September 30, 2013 and December 31, 2012, respectively.
	The Internal Revenue Service, or IRS, is currently reviewing our U.S. income tax returns for the tax years 2010 and 2011. Management believes that we have sufficiently accrued liabilities as of September 30, 2013 for tax exposures, including, but not limited to, exposures related to the review by the IRS of the tax years 2010 and 2011.

Variable_Interest_Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2013
Variable Interest Entities [Abstract]	'
Variable Interest Entities	'
	Variable Interest Entities
	Asset-Backed Investment Securities:
	We invest in various forms of asset-backed securities, which we carry in our investment securities portfolio. These asset-backed securities meet the GAAP definition of asset securitization entities, which are considered to be VIEs as defined by GAAP. We are not considered to be the primary beneficiary of these VIEs, as defined by GAAP, since we do not have control over their activities. Additional information about our asset-backed securities is provided in note 3.
	Tax-Exempt Investment Program:
	In the normal course of our business, we structure and sell certificated interests in pools of tax-exempt investment-grade assets, principally to our mutual fund clients. We structure these pools as partnership trusts, and the assets and liabilities of the trusts are recorded in our consolidated statement of condition as investment securities available for sale and other short-term borrowings. We may also provide liquidity and re-marketing services to the trusts. As of September 30, 2013 and December 31, 2012, we carried investment securities available for sale, composed of securities related to state and political subdivisions, with a fair value of $2.38 billion and $2.68 billion, respectively, and other short-term borrowings of $1.98 billion and $2.15 billion, respectively, in our consolidated statement of condition in connection with these trusts.
	We transfer assets to the trusts from our investment securities portfolio at adjusted book value, and the trusts finance the acquisition of these assets by selling certificated interests issued by the trusts to third-party investors and to State Street as residual holder. These transfers do not meet the de-recognition criteria defined by GAAP, and therefore, are recorded in our consolidated financial statements. The trusts had a weighted-average life of approximately 6.7 years as of September 30, 2013, compared to approximately 6.9 years as of December 31, 2012.
	Under separate legal agreements, we provide standby bond-purchase agreements to these trusts and, with respect to certain securities, letters of credit. Our commitments to the trusts under these standby bond-purchase agreements and letters of credit totaled $2.02 billion and $691 million, respectively, as of September 30, 2013, none of which was utilized at period-end. In the event that our obligations under these agreements are triggered, no material impact to our consolidated results of operations or financial condition is expected to occur, because the securities are already recorded at fair value in our consolidated statement of condition.
	Interests in Sponsored Investment Funds:
	In the normal course of business, we manage various types of sponsored investment funds through SSgA. The services we provide to these sponsored investment funds generate management fee revenue. From time to time, we may invest cash in the funds, which we refer to as seed capital, in order for the funds to establish a performance history for newly-launched strategies. These funds may be considered VIEs. As of September 30, 2013, we have not been deemed to be the primary beneficiary of these funds, and as a result have not included the funds in our consolidated financial statements.
	Our potential maximum loss exposure associated with our investments in these unconsolidated funds totaled $18 million and $28 million as of September 30, 2013 and December 31, 2012, respectively, and represented the carrying value of our seed capital investment, which is recorded in either investment securities available for sale or other assets in our consolidated statement of condition. The amount of loss we may recognize in any period is limited to the carrying amount of our seed capital investment in the unconsolidated fund.

Shareholders_Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2013
Stockholders' Equity Note [Abstract]	'
Shareholders' Equity	'
	Shareholders’ Equity
	Common Stock:
	In March 2013, our Board of Directors approved a program authorizing the purchase by us of up to $2.10 billion of our common stock through March 31, 2014. In the three months ended September 30, 2013, under this program, we purchased approximately 8.2 million shares of our common stock at an average cost of $68.57 per share and an aggregate cost of approximately $560 million. No shares were purchased by us under this program in the three months ended March 31, 2013. From April 1, 2013 through September 30, 2013, we purchased approximately 16.7 million shares of our common stock under this program at an average per-share and aggregate cost of $67.12 and $1.12 billion, respectively. As of September 30, 2013, approximately $980 million remained available for purchases of our common stock under the March 2013 program.
	In the three months ended March 31, 2013, we purchased approximately 6.5 million shares of our common stock at an average cost of $54.95 per share and an aggregate cost of approximately $360 million, under a previous Board-approved program which ended on March 31, 2013.
	In the nine months ended September 30, 2013, under both programs, we purchased in the aggregate approximately 23.2 million shares of our common stock at an average per-share cost of $63.69 and an aggregate cost of approximately $1.48 billion. Shares acquired in connection with our common stock purchase programs which remained unissued as of September 30, 2013 were recorded as treasury stock in our consolidated statement of condition as of September 30, 2013.
	In the three months ended September 30, 2013, we declared a quarterly common stock dividend of $0.26 per share, totaling approximately $115 million. In the three months ended September 30, 2012, we declared a quarterly common stock dividend of $0.24 per share, or approximately $113 million. In the nine months ended September 30, 2013, we declared aggregate common stock dividends of $0.78 per share, totaling approximately $350 million, compared to aggregate common stock dividends of $0.72 per share, totaling approximately $346 million, declared in the nine months ended September 30, 2012.
	Preferred Stock:
	In the three months ended September 30, 2013, we declared a quarterly dividend on our non-cumulative perpetual preferred stock, Series C, of $1,312.50 per share, or approximately $0.33 per depositary share (represented by depositary shares, each representing a 1/4,000th ownership interest in a share of State Street’s non-cumulative perpetual preferred stock, Series C), totaling approximately $7 million. In the nine months ended September 30, 2013, we declared aggregate dividends on our non-cumulative perpetual preferred stock, Series C, of $3,937.50 per share, or approximately $0.98 per depositary share, totaling approximately $20 million. In both the three and nine months ended September 30, 2012, dividends declared on our perpetual preferred stock, Series C, totaled approximately $8 million. In the three and nine months ended September 30, 2012, we declared dividends on our non-cumulative perpetual preferred stock, Series A, totaling approximately $7 million and $21 million, respectively. We redeemed our perpetual preferred stock, Series A, in the three months ended December 31, 2012.
	Accumulated Other Comprehensive Income (Loss):
	The following table presents the after-tax components of accumulated other comprehensive income (loss), or AOCI, as of the dates indicated:
	(In millions)	September 30, 2013			December 31, 2012
	Net unrealized gains on cash flow hedges	$	130		$	69
	Net unrealized gains on available-for-sale securities portfolio	138			815
	Net unrealized losses related to reclassified available-for-sale securities	(81		)	(110		)
	Net unrealized gains on available-for-sale securities	57			705
	Net unrealized losses on available-for-sale securities designated in fair value hedges	(122		)	(183		)
	Other-than-temporary impairment on available-for-sale securities related to factors other than credit	3			(3		)
	Net unrealized losses on hedges of net investments in non-U.S. subsidiaries	(14		)	(14		)
	Other-than-temporary impairment on held-to-maturity securities related to factors other than credit	(51		)	(65		)
	Net unrealized losses on retirement plans	(274		)	(283		)
	Foreign currency translation	157			134
	Total	$	(114	)	$	360
	The following table presents changes in AOCI by component, net of related taxes, in the nine months ended September 30:
		Nine Months Ended September 30, 2013
	(In millions)	Net Unrealized Gains (Losses) on Cash Flow Hedges			Net Unrealized Gains (Losses) on Available-for-Sale Securities			Net Unrealized Losses on Hedges of Net Investments in Non-U.S. Subsidiaries			Other-Than-Temporary Impairment on Held-to-Maturity Securities			Net Unrealized Losses on Retirement Plans			Foreign Currency Translation		Total
	Beginning balance	$	69		$	519		$	(14	)	$	(65	)	$	(283	)	$	134	$	360
	Other comprehensive income (loss) before reclassifications	59			(578		)	—			11			(6		)	22		(492		)
	Amounts reclassified out of AOCI	2			(3		)	—			3			15			1		18
	Other comprehensive income (loss)	61			(581		)	—			14			9			23		(474		)
	Ending balance	$	130		$	(62	)	$	(14	)	$	(51	)	$	(274	)	$	157	$	(114	)
	The following table presents reclassifications out of AOCI in the three and nine months ended September 30, 2013:
		Amount Reclassified out of AOCI						Affected Line Item in Consolidated Statement of Income
	(In millions)	Three Months Ended September 30, 2013			Nine Months Ended September 30, 2013
	Cash flow hedges:
	Interest-rate contracts, net of related taxes of $1	$	—		$	2		Net interest revenue
	Available-for-sale securities:
	Net realized gains from sales of available-for-sale securities, net of related taxes of ($2) and ($4), respectively	(4		)	(7		)	Net gains (losses) from sales of available-for-sale securities
	Other-than-temporary impairment on available-for-sale securities related to factors other than credit, net of related taxes of $2	—			4			Losses reclassified (from) to other comprehensive income
	Held-to-maturity securities:
	Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes of $1 and $3, respectively	1			3			Losses reclassified (from) to other comprehensive income
	Retirement plans:
	Amortization of actuarial losses, net of related taxes of $3 and $9, respectively	5			15			Compensation and employee benefits expense
	Foreign currency translation:
	Sale of foreign entities, net of related taxes of $1	—			1			Processing fees and other revenue
	Total reclassifications out of AOCI	$	2		$	18
	In the nine months ended September 30, 2013, we realized net gains of $11 million, or $7 million net of related taxes as presented in the table above, from sales of available-for-sale securities. Unrealized pre-tax gains of $25 million were included in AOCI as of December 31, 2012, net of deferred taxes of $10 million, related to these sales. In the nine months ended September 30, 2012, we realized net gains of $29 million from sales of available-for-sale securities. Unrealized pre-tax gains of $22 million were included in AOCI as of December 31, 2011, net of deferred taxes of $9 million, related to these sales.

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Financial Instruments	'
	Derivative Financial Instruments
	We use derivative financial instruments to support our clients' needs and to manage our interest-rate and currency risk. In undertaking these activities, we assume positions in both the foreign exchange and interest-rate markets by buying and selling cash instruments and using derivative financial instruments, including foreign exchange forward contracts, foreign exchange and interest-rate options and interest-rate swaps, interest-rate forward contracts and interest-rate futures.
	Interest-rate contracts involve an agreement with a counterparty to exchange cash flows based on the movement of an underlying interest-rate index. An interest-rate swap agreement involves the exchange of a series of interest payments, at either a fixed or variable rate, based on the notional amount without the exchange of the underlying principal amount. An interest-rate option contract provides the purchaser, for a premium, the right, but not the obligation, to receive an interest rate based upon a predetermined notional amount during a specified period. An interest-rate futures contract is a commitment to buy or sell, at a future date, a financial instrument at a contracted price; it may be settled in cash or through the delivery of the contracted instrument.
	Foreign exchange contracts involve an agreement to exchange one currency for another currency at an agreed-upon rate and settlement date. Foreign exchange contracts generally consist of foreign exchange forward and spot contracts, option contracts and cross-currency swaps. Future cash requirements, if any, related to foreign exchange contracts are represented by the gross amount of currencies to be exchanged under each contract unless we and the counterparty have agreed to pay or to receive the net contractual settlement amount on the settlement date.
	Derivative financial instruments involve the management of interest-rate and foreign currency risk, and involve, to varying degrees, market risk and credit and counterparty risk (risk related to repayment). Market risk is defined by U.S. banking regulators as the risk of loss that could result from broad market movements, such as changes in the general level of interest rates, credit spreads, foreign exchange rates or commodity prices. We use a variety of risk management tools and methodologies to measure, monitor and manage the market risk associated with our trading activities. One such risk-management measure is Value-at-Risk, or VaR. VaR is an estimate of potential loss for a given period within a stated statistical confidence interval. We use a risk-measurement system to measure VaR daily. We have adopted standards for measuring VaR, and we maintain regulatory capital for market risk in accordance with currently applicable bank regulatory market risk capital guidelines.
	Derivative financial instruments are also subject to credit and counterparty risk, which is defined as the risk of financial loss if a borrower or counterparty is either unable or unwilling to repay borrowings or settle a transaction in accordance with the underlying contractual terms. We manage credit and counterparty risk by performing credit reviews, maintaining individual counterparty limits, entering into netting arrangements and requiring the receipt of collateral. Collateral requirements are determined after a review of the creditworthiness of each counterparty, and the requirements are monitored and adjusted daily. Collateral is generally held in the form of cash or highly liquid U.S. government securities. We may be required to provide collateral to the counterparty in connection with our entry into derivative financial instruments. Cash collateral received from and provided to counterparties in connection with derivative financial instruments is recorded in accrued expenses and other liabilities and other assets, respectively, in our consolidated statement of condition. As of September 30, 2013 and December 31, 2012, we had recorded approximately $2.87 billion and $1.68 billion, respectively, of cash collateral received from counterparties and approximately $2.80 billion and $1.30 billion, respectively, of cash collateral provided to counterparties in connection with derivative financial instruments in our consolidated statement of condition.
	We enter into master netting agreements with many of our derivative counterparties, and we have elected to net derivative assets and liabilities, including cash collateral received or deposited, which are subject to those agreements. Certain of these agreements contain credit risk-related contingent features in which the counterparty has the option to declare State Street in default and accelerate cash settlement of our net derivative liabilities with the counterparty in the event our credit rating falls below specified levels. The aggregate fair value of all derivative instruments with credit risk-related contingent features that were in a net liability position as of September 30, 2013 totaled approximately $421 million, against which we had no underlying collateral, due to timing differences with respect to the mark-to-market valuation of the collateral. If State Street’s credit rating were downgraded below levels specified in the agreements, the maximum additional amount of payments related to termination events that could have been required pursuant to these contingent features as of September 30, 2013 was approximately $421 million. Such accelerated settlement would not affect our consolidated results of operations.
	Derivatives Not Designated as Hedging Instruments:
	In connection with our trading activities, we use derivative financial instruments in our role as a financial intermediary and as both a manager and servicer of financial assets, in order to accommodate our clients' investment and risk management needs. In addition, we use derivative financial instruments for risk management purposes as economic hedges, which are not formally designated as accounting hedges, in order to contribute to our overall corporate earnings and liquidity. These activities are designed to generate trading services revenue and to manage volatility in our net interest revenue. The level of market risk that we assume is a function of our overall objectives and liquidity needs, our clients' requirements and market volatility.
	With respect to cross-border investing, our clients often enter into foreign exchange forward contracts to convert currency for international investments and to manage the currency risk in their international investment portfolios. As an active participant in the foreign exchange markets, we provide foreign exchange forward contracts and options in support of these client needs, and also act as a dealer in the currency markets. As part of our trading activities, we assume positions in both the foreign exchange and interest-rate markets by buying and selling cash instruments and using derivative financial instruments, including foreign exchange forward contracts, foreign exchange and interest-rate options and interest-rate swaps, interest-rate forward contracts, and interest-rate futures. In the aggregate, we seek to match positions closely with the objective of minimizing related currency and interest-rate risk.
	We offer products that provide book-value protection primarily to plan participants in stable value funds managed by non-affiliated investment managers of post-retirement defined contribution benefit plans, particularly 401(k) plans. We account for the associated contingencies, more fully described in note 8, individually as derivative financial instruments. These contracts are valued quarterly and unrealized losses, if any, are recorded in other expenses in our consolidated statement of income.
	Derivatives Designated as Hedging Instruments:
	In connection with our asset-and-liability management activities, we use derivative financial instruments to manage our interest-rate risk. Interest-rate risk, defined as the sensitivity of income or financial condition to variations in interest rates, is a significant non-trading market risk to which our assets and liabilities are exposed. These hedging relationships are formally designated, and qualify for hedge accounting, as fair value or cash flow hedges. We manage interest-rate risk by identifying, quantifying and hedging our exposures, using fixed-rate portfolio securities and a variety of derivative financial instruments, most frequently interest-rate swaps and options (for example, interest-rate caps and floors). Interest-rate swap agreements alter the interest-rate characteristics of specific balance sheet assets or liabilities. When appropriate, forward-rate agreements, options on swaps, and exchange-traded futures and options are also used.
	Fair value hedges
	Derivatives designated as fair value hedges are utilized to mitigate the risk of changes in fair value of recognized assets and liabilities. Differences between the gains and losses on fair value hedges and the gains and losses on the asset or liability attributable to the hedged risk represent hedge ineffectiveness. We use interest-rate or foreign exchange contracts in this manner to manage our exposure to changes in the fair value of hedged items caused by changes in interest rates or foreign exchange rates.
	We have entered into interest-rate swap agreements to modify our interest revenue from certain available-for-sale investment securities from a fixed rate to a floating rate. The securities hedged had a weighted-average life of approximately 6.7 years as of September 30, 2013, compared to 6.9 years as of December 31, 2012. These securities are hedged with interest-rate swap contracts of similar maturity, repricing and fixed-rate coupons. The interest-rate swap contracts convert the interest revenue from a fixed rate to a floating rate indexed to LIBOR, thereby mitigating our exposure to fluctuations in the fair value of the securities attributable to changes in the benchmark interest rate.
	We have entered into interest-rate swap agreements to modify our interest expense on one senior note and one subordinated note from fixed rates to floating rates. The senior note matures in 2018 and pays fixed interest at a 1.35% annual rate. The subordinated note matures in 2023 and pays fixed interest at a 3.1% annual rate. The senior and subordinated notes are hedged with interest-rate swap contracts with notional amounts, maturities and fixed-rate coupon terms that align with the hedged notes. The interest-rate swap contracts convert the fixed-rate coupons to floating rates indexed to LIBOR, thereby mitigating our exposure to fluctuations in the fair values of the senior notes and subordinated notes stemming from changes in the benchmark interest rates.
	We have entered into forward foreign exchange contracts to hedge the change in fair value attributable to foreign exchange movements in the funding of non-functional currency-denominated investment securities. These forward contracts convert the foreign currency risk to U.S. dollars, thereby mitigating our exposure to fluctuations in the fair value of the securities attributable to changes in foreign exchange rates. Generally, no ineffectiveness is recorded in earnings, since the notional amount of the hedging instruments is aligned with the carrying value of the hedged securities. The forward points on the hedging instruments are considered to be a hedging cost, and accordingly are excluded from the evaluation of hedge effectiveness and recorded in net interest revenue.
	Cash flow hedges
	Derivatives categorized as cash flow hedges are utilized to offset the variability of cash flows to be received from or paid on a floating-rate asset or liability. Ineffectiveness of cash flow hedges is defined as the extent to which the changes in fair value of the derivative exceed the variability of cash flows of the forecasted transaction.
	We have entered into an interest-rate swap agreement to modify our interest revenue from an available-for-sale debt security from a floating rate to a fixed rate. The hedged security had a remaining life of approximately 1 year as of September 30, 2013, compared to 1.8 years as of December 31, 2012. The security is hedged with an interest-rate swap contract of similar maturity, repricing and other characteristics. The interest-rate swap contract converts the interest revenue from a floating rate to a fixed rate, thereby mitigating our exposure to fluctuations in the cash flows of the security attributable to changes in the benchmark interest rate.
	We have entered into foreign exchange contracts to hedge the change in cash flows attributable to foreign exchange movements in the funding of non-functional currency-denominated investment securities. These foreign exchange contracts convert the foreign currency risk to U.S. dollars, thereby mitigating our exposure to fluctuations in the cash flows of the securities attributable to changes in foreign exchange rates. Generally, no ineffectiveness is recorded in earnings, since the critical terms of the hedging instruments and the hedged securities are aligned.
	The following table presents the aggregate contractual, or notional, amounts of derivative financial instruments entered into in connection with our trading and asset-and-liability management activities as of the dates indicated:
	(In millions)	September 30,				December 31,
		2013				2012
	Derivatives not designated as hedging instruments:
	Interest-rate contracts:
	Swap agreements and forwards	$	1,112			$	1,578
	Options and caps purchased	36				68
	Options and caps written	36				68
	Futures	5,126				1,910
	Foreign exchange contracts:
	Forward, swap and spot	1,118,507				897,354
	Options purchased	2,797				9,454
	Options written	2,357				8,734
	Credit derivative contracts:
	Credit swap agreements	136				27
	Other:
	Stable value contracts	27,913				33,512
	Futures	3				—
	Derivatives designated as hedging instruments:
	Interest-rate contracts:
	Swap agreements	4,222				3,153
	Foreign exchange contracts:
	Forward and swap	2,987				3,477
	In connection with our asset-and-liability management activities, we have entered into interest-rate contracts designated as fair value and cash flow hedges to manage our interest-rate risk. The following table presents the aggregate notional amounts of these interest-rate contracts and the related assets or liabilities being hedged as of the dates indicated:
		September 30, 2013												December 31, 2012
	(In millions)	Fair				Cash				Total				Fair				Cash				Total
		Value				Flow								Value				Flow
		Hedges				Hedges								Hedges				Hedges
	Investment securities available for sale	$	2,592			$	130			$	2,722			$	1,573			$	130			$	1,703
	Long-term debt(1)	1,500				—				1,500				1,450				—				1,450
	Total	$	4,092			$	130			$	4,222			$	3,023			$	130			$	3,153
	(1) As of September 30, 2013 and December 31, 2012, fair value hedges of long-term debt increased the carrying value of long-term debt presented in our consolidated statement of condition by $18 million and $174 million, respectively.
	The following table presents the contractual and weighted-average interest rates for long-term debt, which include the effects of the hedges presented in the table above, for the periods indicated:
		Three Months Ended September 30,
		2013						2012
		Contractual			Rate Including			Contractual			Rate Including
		Rates			Impact of Hedges			Rates			Impact of Hedges
	Long-term debt	3.34	%		2.67	%		4.13	%		3.2	%
		Nine Months Ended September 30,
		2013						2012
		Contractual			Rate Including			Contractual			Rate Including
Rates		Impact of Hedges			Rates			Impact of Hedges
Long-term debt	3.49	%		2.77	%		4.01	%		3.2	%
For cash flow hedges, any changes in the fair value of the derivative financial instruments remain in AOCI, and are generally recorded in our consolidated statement of income in future periods when earnings are affected by the variability of the hedged cash flow.
The following tables present the fair value of derivative financial instruments, excluding the impact of master netting agreements, recorded in our consolidated statement of condition as of the dates indicated. The impact of master netting agreements is disclosed in note 2.
	Asset Derivatives
	Balance Sheet		Fair Value
	Location
(In millions)			September 30, 2013				December 31, 2012
Derivatives not designated as hedging instruments:
Foreign exchange contracts	Other assets		$	10,109			$	9,243
Interest-rate contracts	Other assets		34				61
Credit derivative contracts	Other assets		1				—
Total			$	10,144			$	9,304
Derivatives designated as hedging instruments:
Foreign exchange contracts	Other assets		$	257			$	135
Interest-rate contracts	Other assets		24				162
Total			$	281			$	297
	Liability Derivatives
	Balance Sheet		Fair Value
	Location
(In millions)			September 30, 2013				December 31, 2012
Derivatives not designated as hedging instruments:
Foreign exchange contracts	Other liabilities		$	10,210			$	9,067
Interest-rate contracts	Other liabilities		35				61
Other derivative contracts	Other liabilities		9				9
Total			$	10,254			$	9,137
Derivatives designated as hedging instruments:
Interest-rate contracts	Other liabilities		$	272			$	284
Foreign exchange contracts	Other liabilities		51				17
Total			$	323			$	301
The following tables present the impact of our use of derivative financial instruments on our consolidated statement of income for the periods indicated:
	Location of Gain (Loss) on		Amount of Gain (Loss) on Derivative Recognized in
	Derivative in Consolidated		Consolidated Statement
	Statement of Income		of Income
			Three Months Ended								Nine Months Ended
(In millions)			September 30, 2013				September 30, 2012				September 30, 2013				September 30, 2012
Derivatives not designated as hedging instruments:
Foreign exchange contracts	Trading services revenue		$	147			$	113			$	461			$	459
Foreign exchange contracts	Processing fees and other revenue		—				1				—				(2		)
Interest-rate contracts	Trading services revenue		—				1				3				(87		)
Interest-rate contracts	Processing fees and other revenue		—				—				—				2
Credit derivative contracts	Processing fees and other revenue		1				—				1				—
Total			$	148			$	115			$	465			$	372
	Location of Gain (Loss) on Derivative in Consolidated Statement of Income		Amount of Gain								Hedged Item in Fair Value Hedging Relationship		Location of Gain (Loss) on Hedged Item in Consolidated Statement of Income		Amount of Gain
			(Loss) on Derivative												(Loss) on Hedged
			Recognized  in												Item Recognized in
			Consolidated												Consolidated
			Statement of Income												Statement of Income
			Three Months Ended September 30, 2013				Nine Months Ended September 30, 2013								Three Months Ended September 30, 2013				Nine Months Ended September 30, 2013
(In millions)
Derivatives designated as fair value hedges:
Foreign exchange contracts	Processing fees and		$	20			$	(135	)		Investment securities		Processing fees and		$	(20	)		$	135
	other revenue												other revenue
Interest-rate contracts	Processing fees and		(14		)		(146		)		Long-term debt		Processing fees and		12				133
	other revenue												other revenue
Interest-rate contracts	Processing fees and		(6		)		15				Available-for-sale securities		Processing fees and		7				(15		)
	other revenue												other revenue
Total			$	—			$	(266	)						$	(1	)		$	253
	Location of Gain (Loss) on Derivative in Consolidated Statement of Income		Amount of Gain								Hedged Item in Fair Value Hedging Relationship		Location of  Gain (Loss) on Hedged Item  in Consolidated Statement  of Income		Amount of Gain
			(Loss) on Derivative												(Loss) on Hedged
			Recognized  in												Item Recognized in
			Consolidated												Consolidated
			Statement of Income												Statement of Income
			Three Months Ended September 30, 2012				Nine Months Ended September 30, 2012								Three Months Ended September 30, 2012				Nine Months Ended September 30, 2012
(In millions)
Derivatives designated as fair value hedges:
Foreign exchange contracts	Processing fees and		$	26			$	30			Investment securities		Processing fees and		$	(26	)		$	(30	)
	other revenue												other revenue
Interest-rate contracts	Processing fees and		(1		)		(7		)		Available-for-sale securities		Processing fees and		1				3
	other revenue												other revenue
Interest-rate contracts	Processing fees and		22				62				Long-term debt		Processing fees and		(21		)		(58		)
	other revenue												other revenue
Total			$	47			$	85							$	(46	)		$	(85	)
Differences between the gains (losses) on the derivative and the gains (losses) on the hedged item, excluding any amounts recorded in net interest revenue, represent hedge ineffectiveness.
	Amount of Gain								Location of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income		Amount of Gain								Location of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income		Amount of Gain
	(Loss) on Derivative										(Loss) Reclassified										(Loss) on Derivative
	Recognized in Other										from OCI to										Recognized in
	Comprehensive										Consolidated										Consolidated
	Income										Statement of Income										Statement of Income
	Three Months Ended September 30, 2013				Nine Months Ended September 30, 2013						Three Months Ended September 30, 2013				Nine Months Ended September 30, 2013						Three Months Ended September 30, 2013		Nine Months Ended September 30, 2013
(In millions)
Derivatives designated as cash flow hedges:
Interest-rate contracts	$	(1	)		$	10			Net interest revenue		$	(1	)		$	(3	)		Net interest revenue		$	1	$	3
Foreign exchange contracts	(55		)		98				Net interest revenue		—				—				Net interest revenue		—		5
Total	$	(56	)		$	108					$	(1	)		$	(3	)				$	1	$	8
	Amount of Gain								Location of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income		Amount of Gain								Location of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income		Amount of Gain
	(Loss) on Derivative										(Loss) Reclassified										(Loss) on Derivative
	Recognized in Other										from OCI to										Recognized in
	Comprehensive										Consolidated										Consolidated
	Income										Statement of Income										Statement of Income
	Three Months Ended September 30, 2012				Nine Months Ended September 30, 2012						Three Months Ended September 30, 2012				Nine Months Ended September 30, 2012						Three Months Ended September 30, 2012		Nine Months Ended September 30, 2012
(In millions)
Derivatives designated as cash flow hedges:
Interest-rate contracts	$	—			$	3			Net interest revenue		$	(1	)		$	(4	)		Net interest revenue		$	1	$	2
Foreign exchange contracts	(2		)		(1		)		Net interest revenue		—				—				Net interest revenue		2		2
Total	$	(2	)		$	2					$	(1	)		$	(4	)				$	3	$	4

Offsetting_Arrangements

Offsetting Arrangements	9 Months Ended
	Sep. 30, 2013
Offsetting [Abstract]	'
Offsetting Arrangements	'
	Offsetting Arrangements
	We manage credit and counterparty risk by entering into enforceable netting agreements and other collateral arrangements with counterparties to derivative financial instruments and secured financing transactions, including resale and repurchase agreements, and principal securities borrowing and lending agreements. These netting agreements mitigate our counterparty credit risk by providing for a single net settlement with a counterparty of all financial transactions covered by the agreement in an event of default as defined under such agreement. In limited cases, a netting agreement may also provide for the periodic netting of settlement payments with respect to multiple different transaction types in the normal course of business.
	Certain of our derivative contracts are executed under either standardized netting agreements or, for exchange-traded derivatives, the relevant contracts for a particular exchange which contain enforceable netting provisions. In certain cases, we may have cross-product netting arrangements which allow for netting and set-off of a variety of types of derivatives with a single counterparty. A derivative netting arrangement creates an enforceable right of set-off that becomes effective, and effects the realization or settlement of individual financial assets and liabilities, only following a specified event of default. Collateral requirements associated with our derivative contracts are determined after a review of the creditworthiness of each counterparty, and the requirements are monitored and adjusted daily, typically based on net exposure by counterparty. Collateral is generally in the form of cash or highly liquid U.S. government securities.
	In connection with our secured financing activities, we enter into netting agreements and other collateral arrangements with counterparties, which provide for the right to liquidate collateral upon an event of default. Required collateral is generally in the form of cash, equity securities or fixed-income securities. Default events may include the failure to make payments or deliver securities timely, material adverse changes in financial condition or insolvency, the breach of minimum regulatory capital requirements, or loss of license, charter or other legal authorization necessary to perform under the contract.
	In order for an arrangement to be eligible for netting, we must have a basis to conclude that such netting arrangements are legally enforceable. The analysis of the legal enforceability of an arrangement differs by jurisdiction, depending on the laws of that jurisdiction. In many jurisdictions, specific legislation exists that provides for the enforceability in bankruptcy of close-out netting under a netting agreement, typically by way of specific exception from more general prohibitions on the exercise of creditor rights.
	When we have a basis to conclude that a legally enforceable netting arrangement exists between us and the derivative counterparty and the relevant transaction is the type of transaction that is recorded in our consolidated statement of condition, we offset derivative assets and liabilities, and the related collateral received and provided, in our consolidated statement of condition. We also offset secured financing assets and liabilities with the same counterparty or clearinghouse which have the same maturity date and are settled in the normal course of business on a net basis.
	The following tables present information about the offsetting of derivative financial instruments and secured financing transactions, as of the dates indicated:
	Assets:	30-Sep-13								31-Dec-12
	(In millions)	Gross Amounts of Recognized Assets(1)		Gross Amounts Offset in Statement of Condition(2)			Net Amounts of Assets Presented in Statement of Condition			Gross Amounts of Recognized Assets(1)		Gross Amounts Offset in Statement of Condition(2)			Net Amounts of Assets Presented in Statement of Condition
	Derivatives:
	Interest-rate contracts	$	58	$	(45	)	$	13		$	223	$	(19	)	$	204
	Foreign exchange contracts	10,366		(3,757		)	6,609			9,378		(3,575		)	5,803
	Other derivative contracts	1		—			1			—		—			—
	Cash collateral netting	—		(2,303		)	(2,303		)	—		(1,451		)	(1,451		)
	Total derivatives	$	10,425	$	(6,105	)	$	4,320		$	9,601	$	(5,045	)	$	4,556
	Other financial instruments:
	Resale agreements and securities borrowing(3)	$	45,563	$	(29,974	)	$	15,589		$	35,658	$	(23,809	)	$	11,849
	Total derivatives and other financial instruments	$	55,988	$	(36,079	)	$	19,909		$	45,259	$	(28,854	)	$	16,405
	(1) Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.
	(2) Amounts subject to netting arrangements which have been determined to be legally enforceable.
	(3) Included in the $15,589 million as of September 30, 2013 was $5,827 million of resale agreements and $9,762 million of collateral related to securities borrowing. Included in the $11,849 million as of December 31, 2012 was $5,016 million of resale agreements and $6,833 million of collateral related to securities borrowing. Resale agreements and collateral related to securities borrowing were recorded in securities purchased under resale agreements and other assets, respectively, in our consolidated statement of condition. Refer to note 8 for additional information with respect to principal securities finance transactions.
		30-Sep-13										31-Dec-12
				Gross Amounts Not Offset in Statement of Condition(1)											Gross Amounts Not Offset in Statement of Condition(1)
	(In millions)	Net Amount of Assets Presented in Statement of Condition		Counterparty Netting			Collateral Received			Net Amount(2)		Net Amount of Assets Presented in Statement of Condition			Counterparty Netting			Collateral Received			Net Amount(2)
	Derivatives	$	4,320	$	—		$	(95	)	$	4,225	$	4,556		$	—		$	(105	)	$	4,451
	Resale agreements and securities borrowing	15,589		(144		)	(15,360		)	85		11,849			(126		)	(11,626		)	97
	Total	$	19,909	$	(144	)	$	(15,455	)	$	4,310	$	16,405		$	(126	)	$	(11,731	)	$	4,548
	(1) Amounts subject to netting arrangements which have been determined to be legally enforceable.
	(2) Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements.
	The following tables present information about the offsetting of derivative financial instruments and secured financing transactions, as of the dates indicated:
	Liabilities:	30-Sep-13								31-Dec-12
	(In millions)	Gross Amounts of Recognized Liabilities(1)		Gross Amounts Offset in Statement of Condition(2)			Net Amounts of Liabilities Presented in Statement of Condition			Gross Amounts of Recognized Liabilities(1)		Gross Amounts Offset in Statement of Condition(2)			Net Amounts of Liabilities Presented in Statement of Condition
	Derivatives:
	Interest-rate contracts	$	307	$	(45	)	$	262		$	345	$	(19	)	$	326
	Foreign exchange contracts	10,261		(3,757		)	6,504			9,084		(3,574		)	5,510
	Other derivative contracts	9		—			9			9		—			9
	Cash collateral netting	—		(468		)	(468		)	—		(478		)	(478		)
	Total derivatives	$	10,577	$	(4,270	)	$	6,307		$	9,438	$	(4,071	)	$	5,367
	Other financial instruments:
	Repurchase agreements and securities lending(3)	$	46,488	$	(29,974	)	$	16,514		$	36,801	$	(23,809	)	$	12,992
	Total derivatives and other financial instruments	$	57,065	$	(34,244	)	$	22,821		$	46,239	$	(27,880	)	$	18,359
	(1) Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.
	(2) Amounts subject to netting arrangements which have been determined to be legally enforceable.
	(3) Included in the $16,514 million as of September 30, 2013 was $10,123 million of repurchase agreements and $6,391 million of collateral related to securities lending. Included in the $12,992 million as of December 31, 2012 was $8,006 million of repurchase agreements and $4,986 million of collateral related to securities lending. Repurchase agreements and collateral related to securities lending were recorded in securities sold under repurchase agreements and accrued expenses and other liabilities, respectively, in our consolidated statement of condition. Refer to note 8 for additional information with respect to principal securities finance transactions.
		30-Sep-13										31-Dec-12
				Gross Amounts Not Offset in Statement of Condition(1)											Gross Amounts Not Offset in Statement of Condition(1)
	(In millions)	Net Amount of Liabilities Presented in Statement of Condition		Counterparty Netting			Collateral Provided			Net Amount(2)		Net Amount of Liabilities Presented in Statement of Condition			Counterparty Netting			Collateral Provided			Net Amount(2)
	Derivatives	$	6,307	$	—		$	—		$	6,307	$	5,367		$	—		$	—		$	5,367
	Repurchase agreements and securities lending	$	16,514	$	(144	)	$	(14,002	)	2,368		12,992			(126		)	(12,067		)	799
	Total	$	22,821	$	(144	)	$	(14,002	)	$	8,675	$	18,359		$	(126	)	$	(12,067	)	$	6,166
	(1) Amounts subject to netting arrangements which have been determined to be legally enforceable.
	(2) Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements.

Net_Interest_Revenue

Net Interest Revenue	9 Months Ended
	Sep. 30, 2013
Net Interest Revenue [Abstract]	'
Net Interest Revenue	'
	Net Interest Revenue
	The following table presents the components of interest revenue and interest expense, and related net interest revenue, for the periods indicated:
		Three Months Ended September 30,				Nine Months Ended September 30,
	(In millions)	2013		2012		2013		2012
	Interest revenue:
	Deposits with banks	$	29	$	31	$	91	$	108
	Investment securities:
	U.S. Treasury and federal agencies	165		200		542		605
	State and political subdivisions	59		53		164		161
	Other investments	323		374		1,003		1,185
	Securities purchased under resale agreements	8		15		33		37
	Loans and leases	58		57		193		183
	Other interest-earning assets	1		—		4		2
	Total interest revenue	643		730		2,030		2,281
	Interest expense:
	Deposits	17		37		78		127
	Short-term borrowings	15		18		46		55
	Long-term debt	59		52		169		172
	Other interest-bearing liabilities	6		4		19		11
	Total interest expense	97		111		312		365
	Net interest revenue	$	546	$	619	$	1,718	$	1,916

Acquisition_and_Restructuring_

Acquisition and Restructuring Costs	9 Months Ended
	Sep. 30, 2013
Other Expenses [Abstract]	'
Expenses	'
	Acquisition and Restructuring Costs
	The following table presents net acquisition and restructuring costs recorded in the periods indicated:
			Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)		2013			2012			2013			2012
	Acquisition costs		$	18		$	13		$	52		$	41
	Restructuring charges, net		12			15			22			45
	Total acquisition and restructuring costs		$	30		$	28		$	74		$	86
	Acquisition Costs
	Acquisition costs incurred in the three and nine months ended September 30, 2013 and the three and nine months ended September 30, 2012 were related to previously disclosed acquisitions.
	Restructuring Charges
	Information with respect to our Business Operations and Information Technology Transformation program and our 2011 and 2012 expense control measures, including charges, employee reductions and aggregate activity in the related accruals, is provided in the two sections that follow.
	Business Operations and Information Technology Transformation Program
	In November 2010, we announced a global multi-year Business Operations and Information Technology Transformation program. The program includes operational, information technology and targeted cost initiatives, including plans related to reductions in both staff and occupancy costs. To date, we have recorded aggregate restructuring charges of $375 million in our consolidated statement of income, composed of $156 million in 2010, $133 million in 2011, $67 million in 2012 and $19 million in the nine months ended September 30, 2013.
	The charges related to the program included costs related to severance, benefits and outplacement services, as well as costs which resulted from actions taken to reduce our occupancy costs through the consolidation of leases and properties. The charges also included costs related to information technology, including transition fees associated with the expansion of our use of third-party service providers associated with components of our information technology infrastructure and application maintenance and support.
	In 2010, in connection with the program, we initiated the involuntary termination of 1,400 employees, or approximately 5% of our global workforce, which we had substantially completed by the end of 2011. In addition, in connection with our announcement in 2011 of the expansion of our use of third-party service providers associated with our information technology infrastructure and application maintenance and support, as well as the continued execution of the business operations transformation component of the program, we have identified 1,234 additional involuntary terminations and role eliminations, including 263 in the nine months ended September 30, 2013. As of September 30, 2013, we have eliminated 1,168 of these positions.
	Expense Control Measures
	In December 2011, in connection with expense control measures designed to calibrate our expenses to our outlook for our capital markets-facing businesses in 2012, we took two actions. First, we withdrew from our fixed-income trading initiative, in which we traded in fixed-income securities and derivatives as principal with our custody clients and other third-parties that trade in these securities and derivatives. Second, we undertook other targeted staff reductions. As a result of these actions, we recorded aggregate pre-tax restructuring charges of $120 million in 2011 and net pre-tax credit adjustments of $(1) million in 2012 in our consolidated statement of income.
	The charges recorded in 2011 included costs related to severance, benefits and outplacement services with respect to both our withdrawal from our fixed-income initiative and the other targeted staff reductions; costs associated with fair-value adjustments to the initiative's trading portfolio resulting from our decision to withdraw from the initiative; and costs for asset and other write-offs related to asset write-downs and contract terminations. In 2011, in connection with the above-described employee-related actions, we identified 442 employees to be involuntarily terminated as their roles were eliminated. As of September 30, 2013, we had substantially completed these reductions.
	In December 2012, in connection with expense control measures designed to better align our expenses to our business strategy and related outlook for 2013, we identified additional targeted staff reductions. As a result of these actions, we have recorded aggregate pre-tax restructuring charges of $133 million in 2012 and $3 million in the nine months ended September 30, 2013, which included $1 million in the three months ended September 30, 2013, in our consolidated statement of income. Employee-related costs included severance, benefits and outplacement services. Costs for asset and other write-offs were primarily related to contract terminations. We originally identified involuntary terminations and role eliminations of 960 employees (630 positions after replacements).  As of September 30, 2013, 720 positions had been eliminated through voluntary and involuntary terminations.
	Aggregate Restructuring-Related Accrual Activity
	The following table presents aggregate activity associated with accruals that resulted from the charges associated with the Business Operations and Information Technology Transformation program and the 2011 and 2012 expense control measures:
	(In millions)	Employee-			Real Estate Consolidation			Information Technology Costs			Asset and Other Write-Offs			Total
		Related
		Costs
	Balance as of December 31, 2012	$	195		$	49		$	5		$	13		$	262
	Additional accruals for Business Operations and Information Technology Transformation program	9			11			(1		)	—			19
	Additional accruals for 2012 expense control measures	(2		)	—			—			5			3
	Payments and adjustments	(125		)	(11		)	(4		)	(8		)	(148		)
	Balance as of September 30, 2013	$	77		$	49		$	—		$	10		$	136

Earnings_Per_Common_Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Common Share	'
	Earnings Per Common Share
	The following table presents the computation of basic and diluted earnings per common share for the periods indicated:
		Three Months Ended September 30,						Nine Months Ended September 30,
	(Dollars in millions, except per share amounts)	2013			2012			2013			2012
	Net income	$	540		$	674		$	1,583		$	1,591
	Less:
	Preferred stock dividends	(7		)	(15		)	(20		)	(29		)
	Dividends and undistributed earnings allocated to participating securities(1)	(2		)	(5		)	(6		)	(11		)
	Net income available to common shareholders	$	531		$	654		$	1,557		$	1,551
	Average common shares outstanding (in thousands):
	Basic average common shares	442,860			472,355			449,742			479,536
	Effect of dilutive securities: common stock options and common stock awards	9,294			7,655			8,650			6,277
	Diluted average common shares	452,154			480,010			458,392			485,813
	Anti-dilutive securities(2)	1,788			5,443			2,384			5,613
	Earnings per Common Share:
	Basic	$	1.2		$	1.39		$	3.46		$	3.23
	Diluted	1.17			1.36			3.4			3.19
	(1) Represented the portion of net income available to common equity allocated to participating securities; participating securities, composed of unvested restricted stock and director stock awards, contain non-forfeitable rights to dividends during the vesting period on a basis equivalent to dividends paid to common shareholders.
	(2) Represented common stock options and other equity-based awards outstanding, but not included in the computation of diluted average shares because their effect was anti-dilutive.

Line_of_Business_Information

Line of Business Information	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Line of Business Information	'
	Line of Business Information
	We have two lines of business: Investment Servicing and Investment Management. Given our services and management organization, the results of operations for these lines of business are not necessarily comparable with those of other companies, including companies in the financial services industry. Information about our two lines of business, as well as revenues, expenses and capital allocation methodologies associated with these lines of business, is provided in note 24 to the consolidated financial statements included in our 2012 Form 10-K.
	The following tables provide a summary of our line of business results for the periods indicated. The “Other” column for the third quarter and first nine months of 2013 included net acquisition and restructuring costs of $30 million and $74 million, respectively, and certain provisions for litigation exposure and other costs of $5 million and $20 million, respectively. The third quarter and first nine months of 2012 included the $362 million credit related to recoveries associated with the 2008 Lehman Brothers bankruptcy, as well as certain provisions for litigation exposure and other costs of $85 million and $107 million, respectively, and net acquisition and restructuring costs of $28 million and $86 million, respectively. In addition, the first nine months of 2012 included the net realized loss from the sale of all of our Greek investment securities. The amounts in the “Other” columns were not allocated to State Street's business lines. Results for 2012 reflect reclassifications, for comparative purposes, related to management changes in methodology associated with funds transfer pricing and expense allocation reflected in results for 2013.
		Three Months Ended September 30,
	(Dollars in millions,	Investment						Investment						Other						Total
	except where otherwise noted)	Servicing						Management
		2013			2012			2013			2012			2013			2012			2013			2012
	Fee revenue:
	Servicing fees	$	1,211		$	1,100		$	—		$	—		$	—		$	—		$	1,211		$	1,100
	Management fees	—			—			276			251			—			—			276			251
	Trading services	242			208			14			24			—			—			256			232
	Securities finance	69			81			5			10			—			—			74			91
	Processing fees and other	60			38			6			7			—			—			66			45
	Total fee revenue	1,582			1,427			301			292			—			—			1,883			1,719
	Net interest revenue	527			600			19			19									546			619
	Gains (losses) related to investment securities, net	(4		)	18			—			—			—			—			(4		)	18
	Total revenue	2,105			2,045			320			311			—			—			2,425			2,356
	Total expenses	1,496			1,459			191			205			35			(249		)	1,722			1,415
	Income before income tax expense	$	609		$	586		$	129		$	106		$	(35	)	$	249		$	703		$	941
	Pre-tax margin	29		%	29		%	40		%	34		%							29		%	40		%
	Average assets (in billions)	$	197.7		$	192.1		$	3.6		$	3.7								$	201.3		$	195.8
		Nine Months Ended September 30,
	(Dollars in millions,	Investment						Investment						Other						Total
	except where otherwise noted)	Servicing						Management
		2013			2012			2013			2012			2013			2012			2013			2012
	Fee revenue:
	Servicing fees	$	3,587		$	3,264		$	—		$	—		$	—		$	—		$	3,587		$	3,264
	Management fees	—			—			816			733			—			—			816			733
	Trading services	778			695			55			72			—			—			833			767
	Securities finance	255			296			28			35			—			—			283			331
	Processing fees and other	181			183			11			4			—			—			192			187
	Total fee revenue	4,801			4,438			910			844			—			—			5,711			5,282
	Net interest revenue	1,655			1,858			63			58			—			—			1,718			1,916
	Gains (losses) related to investment securities, net	(9		)	48			—			—			—			(46		)	(9		)	2
	Total revenue	6,447			6,344			973			902			—			(46		)	7,420			7,200
	Provision for loan losses	—			(1		)	—			—			—			—			—			(1		)
	Total expenses	4,628			4,537			624			654			94			(169		)	5,346			5,022
	Income before income tax expense	$	1,819		$	1,808		$	349		$	248		$	(94	)	$	123		$	2,074		$	2,179
	Pre-tax margin	28		%	28		%	36		%	27		%							28		%	30		%
	Average assets (in billions)	$	201.9		$	187.2		$	3.8		$	3.8								$	205.7		$	191

NonUS_Activities

Non-U.S. Activities	9 Months Ended
	Sep. 30, 2013
Segments, Geographical Areas [Abstract]	'
Non-U.S. Activities	'
	Non-U.S. Activities
	We generally define our non-U.S. activities as those revenue-producing business activities that arise from clients domiciled outside the U.S. Due to the integrated nature of our business, precise segregation of our U.S. and non-U.S. activities is not possible. Subjective estimates and other judgments have been applied to determine the financial results and assets related to our non-U.S. activities, including our application of funds transfer pricing, our asset-and-liability management policies and our allocation of certain indirect corporate expenses. Interest expense allocations are based on our internal funds transfer pricing methodology.
	The following table presents our non-U.S. financial results for the periods indicated. Results for 2012 reflect changes in methodology associated with funds transfer pricing and expense allocation reflected in results for 2013.
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Total fee revenue	$	771		$	700		$	2,347		$	2,169
	Net interest revenue	306			240			874			709
	Gains (losses) related to investment securities, net	(2		)	(4		)	(12		)	(36		)
	Total revenue	1,075			936			3,209			2,842
	Expenses	786			708			2,279			2,226
	Income before income taxes	289			228			930			616
	Income tax expense	74			57			228			153
	Net income	$	215		$	171		$	702		$	463
	The following table presents the significant components of our non-U.S. assets as of the dates indicated, based on the domicile of the underlying counterparties:
	(In millions)	September 30, 2013			December 31, 2012
	Interest-bearing deposits with banks	$	5,221		$	20,665
	Investment securities	30,586			28,976
	Other assets	16,982			13,441
	Total non-U.S. assets	$	52,789		$	63,082

Variable_Interest_Entities_Acc

Variable Interest Entities Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Variable Interest Entities [Abstract]	'
Asset-Backed Securitization Trusts	'
	We invest in various forms of asset-backed securities, which we carry in our investment securities portfolio. These asset-backed securities meet the GAAP definition of asset securitization entities, which are considered to be VIEs as defined by GAAP. We are not considered to be the primary beneficiary of these VIEs, as defined by GAAP, since we do not have control over their activities. Additional information about our asset-backed securities is provided in note 3.
Tax-Exempt Investment Program	'
	Tax-Exempt Investment Program:
	In the normal course of our business, we structure and sell certificated interests in pools of tax-exempt investment-grade assets, principally to our mutual fund clients. We structure these pools as partnership trusts, and the assets and liabilities of the trusts are recorded in our consolidated statement of condition as investment securities available for sale and other short-term borrowings. We may also provide liquidity and re-marketing services to the trusts. As of September 30, 2013 and December 31, 2012, we carried investment securities available for sale, composed of securities related to state and political subdivisions, with a fair value of $2.38 billion and $2.68 billion, respectively, and other short-term borrowings of $1.98 billion and $2.15 billion, respectively, in our consolidated statement of condition in connection with these trusts.
	We transfer assets to the trusts from our investment securities portfolio at adjusted book value, and the trusts finance the acquisition of these assets by selling certificated interests issued by the trusts to third-party investors and to State Street as residual holder. These transfers do not meet the de-recognition criteria defined by GAAP, and therefore, are recorded in our consolidated financial statements. The trusts had a weighted-average life of approximately 6.7 years as of September 30, 2013, compared to approximately 6.9 years as of December 31, 2012.
	Under separate legal agreements, we provide standby bond-purchase agreements to these trusts and, with respect to certain securities, letters of credit. Our commitments to the trusts under these standby bond-purchase agreements and letters of credit totaled $2.02 billion and $691 million, respectively, as of September 30, 2013, none of which was utilized at period-end. In the event that our obligations under these agreements are triggered, no material impact to our consolidated results of operations or financial condition is expected to occur, because the securities are already recorded at fair value in our consolidated statement of condition.

Fair_Value_Tables

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The following tables present information with respect to our financial assets and liabilities carried at fair value in our consolidated statement of condition on a recurring basis as of the dates indicated. No transfers of financial assets or liabilities between levels 1 and 2 occurred during the nine months ended September 30, 2013 or the year ended December 31, 2012.
		Fair-Value Measurements on a Recurring Basis
		as of September 30, 2013
	(In millions)	Quoted Market			Pricing Methods				Pricing Methods				Impact of Netting(1)			Total Net
		Prices in Active			with Significant				with Significant							Carrying Value
		Markets			Observable				Unobservable							in Consolidated
		(Level 1)			Market Inputs				Market Inputs							Statement of
					(Level 2)				(Level 3)							Condition
	Assets:
	Trading account assets:
	U.S. government securities	$	20													$	20
	Non-U.S. government securities	392														392
	Other	66			$	438										504
	Total trading account assets	478			438											916
	Investment securities available for sale:
	U.S. Treasury and federal agencies:
	Direct obligations	—			738											738
	Mortgage-backed securities	—			23,834				$	741						24,575
	Asset-backed securities:
	Student loans	—			14,503				368							14,871
	Credit cards	—			8,602				24							8,626
	Sub-prime	—			1,266				—							1,266
	Other	—			551				4,350							4,901
	Total asset-backed securities	—			24,922				4,742							29,664
	Non-U.S. debt securities:
	Mortgage-backed securities	—			10,661				340							11,001
	Asset-backed securities	—			4,668				799							5,467
	Government securities	—			3,541				—							3,541
	Other	—			4,159				441							4,600
	Total non-U.S. debt securities	—			23,029				1,580							24,609
	State and political subdivisions	—			9,254				44							9,298
	Collateralized mortgage obligations	—			4,971				187							5,158
	Other U.S. debt securities	—			5,036				9							5,045
	U.S. equity securities	—			39				—							39
	Non-U.S. equity securities	—			2				—							2
	U.S. money-market mutual funds	—			680				—							680
	Non-U.S. money-market mutual funds	—			174				—							174
	Total investment securities available for sale	—			92,679				7,303							99,982
	Other assets:
	Derivative instruments:
	Foreign exchange contracts	—			10,289				77				$	(6,060	)	4,306
	Interest-rate contracts	—			58				—				(45		)	13
	Other	—			1				—				—			1
	Total derivative instruments	—			10,348				77				(6,105		)	4,320
	Other	101			—				—				—			101
	Total assets carried at fair value	$	579		$	103,465			$	7,380			$	(6,105	)	$	105,319
	Liabilities:
	Accrued expenses and other liabilities:
	Derivative instruments:
	Foreign exchange contracts				$	10,206			$	55			$	(4,211	)	$	6,050
	Interest-rate contracts				307				—				(59		)	248
	Other				—				9				—			9
	Total derivative instruments				10,513				64				(4,270		)	6,307
	Other	$	101		—				—				—			101
	Total liabilities carried at fair value	$	101		$	10,513			$	64			$	(4,270	)	$	6,408
	(1) Represents counterparty netting against level-2 financial assets and liabilities, where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $2.30 billion and $468 million, respectively, for cash collateral received from and provided to derivative counterparties.
		Fair-Value Measurements on a Recurring Basis
		as of December 31, 2012
	(In millions)	Quoted Market			Pricing Methods				Pricing Methods				Impact of Netting(1)			Total Net
		Prices in Active			with Significant				with Significant							Carrying Value
		Markets			Observable				Unobservable							in Consolidated
		(Level 1)			Market Inputs				Market Inputs							Statement of
					(Level 2)				(Level 3)							Condition
Assets:
Trading account assets:
U.S. government securities	$	20													$	20
Non-U.S. government securities	391														391
Other	71			$	155										226
Total trading account assets	482			155											637
Investment securities available for sale:
U.S. Treasury and federal agencies:
Direct obligations	3			838											841
Mortgage-backed securities	—			31,387				$	825						32,212
Asset-backed securities:
Student loans	—			15,833				588							16,421
Credit cards	—			9,919				67							9,986
Sub-prime	—			1,399				—							1,399
Other	—			683				3,994							4,677
Total asset-backed securities	—			27,834				4,649							32,483
Non-U.S. debt securities:
Mortgage-backed securities	—			10,850				555							11,405
Asset-backed securities	—			5,694				524							6,218
Government securities	—			3,199				—							3,199
Other	—			4,166				140							4,306
Total non-U.S. debt securities	—			23,909				1,219							25,128
State and political subdivisions	—			7,503				48							7,551
Collateralized mortgage obligations	—			4,837				117							4,954
Other U.S. debt securities	—			5,289				9							5,298
U.S. equity securities	—			31				—							31
Non-U.S. equity securities	—			1				—							1
U.S. money-market mutual funds	—			1,062				—							1,062
Non-U.S. money-market mutual funds	—			121				—							121
Total investment securities available for sale	3			102,812				6,867							109,682
Other assets:
Derivatives instruments:
Foreign exchange contracts	—			9,265				113				$	(4,981	)	4,397
Interest-rate contracts	—			223				—				(64		)	159
Total derivative instruments	—			9,488				113				(5,045		)	4,556
Other	66			2				—				—			68
Total assets carried at fair value	$	551		$	112,457			$	6,980			$	(5,045	)	$	114,943
Liabilities:
Accrued expenses and other liabilities:
Derivative instruments:
Foreign exchange contracts				$	8,978			$	106			$	(4,052	)	$	5,032
Interest-rate contracts				345				—				(19		)	326
Other				—				9				—			9
Total derivative instruments				9,323				115				(4,071		)	5,367
Other	$	66		—				—				—			66
Total liabilities carried at fair value	$	66		$	9,323			$	115			$	(4,071	)	$	5,433
(1) Represents counterparty netting against level-2 financial assets and liabilities, where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $1.45 billion and $478 million, respectively, for cash collateral received from and provided to derivative counterparties.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	'
		Fair-Value Measurements Using Significant Unobservable Inputs
		Nine Months Ended September 30, 2013
		Fair			Transfers				Transfers				Total Realized and						Purchases		Issuances		Sales				Settlements			Fair			Change in
		Value as of			into				out of				Unrealized Gains (Losses)																	Value as of			Unrealized
		December 31,			Level 3				Level 3																					September 30,			Gains
		2012																												2013			(Losses)
																																	Related to
																																	Financial
																																	Instruments
																																	Held as of
																																	September 30,
	(In millions)												Recorded			Recorded																	2013
													in			in Other
													Revenue			Comprehensive
																Income
	Assets:
	Investment securities available for sale:
	U.S. Treasury and federal agencies, mortgage-backed securities	$	825						$	(92	)					$	(1	)	$	92							$	(83	)	$	741
	Asset-backed securities:
	Student loans	588							(175		)		$	1		6			—				$	(26	)		(26		)	368
	Credit cards	67							—				—			—			—				—				(43		)	24
	Other	3,994							—				40			25			1,358				(33		)		(1,034		)	4,350
	Total asset-backed securities	4,649							(175		)		41			31			1,358				(59		)		(1,103		)	4,742
	Non-U.S. debt securities:
	Mortgage-backed securities	555							(208		)		—			(1		)	—				—				(6		)	340
	Asset-backed securities	524			$	139			(181		)		4			2			399				—				(88		)	799
	Other	140			—				(40		)		—			—			328				—				13			441
	Total non-U.S. debt securities	1,219			139				(429		)		4			1			727				—				(81		)	1,580
	State and political subdivisions	48			—				—				—			(1		)	—				—				(3		)	44
	Collateralized mortgage obligations	117			15				(100		)		1			(5		)	190				—				(31		)	187
	Other U.S. debt securities	9			—				—				—			—			—				—				—			9
	Total investment securities available for sale	6,867			154				(796		)		46			25			2,367				(59		)		(1,301		)	7,303
	Other assets:
	Derivative instruments, Foreign exchange contracts	113			—				—				119			—			25				—				(180		)	77			$	29
	Total assets carried at fair value	$	6,980		$	154			$	(796	)		$	165		$	25		$	2,392	—		$	(59	)		$	(1,481	)	$	7,380		$	29
		Fair-Value Measurements Using Significant Unobservable Inputs
		Three Months Ended September 30, 2012
		Fair			Transfers				Transfers				Total Realized and						Purchases		Issuances		Sales				Settlements			Fair			Change in
		Value as of June 30,			into				out of				Unrealized Gains (Losses)																	Value as of			Unrealized
		2012			Level 3				Level 3																					30-Sep-12			Gains
																																	(Losses)
																																	Related to
																																	Financial
																																	Instruments
																																	Held as of
																																	September 30,
	(In millions)												Recorded			Recorded																	2012
													in			in Other
													Revenue			Comprehensive
																Income
	Assets:
	Investment securities available for sale:
	U.S. Treasury and federal agencies:
	Direct obligations
	Mortgage-backed securities	$	933													$	3										$	(30	)	$	906
	Asset-backed securities:
	Student loans	484											$	1		5											(12		)	478
	Credit cards	274							$	(36	)		1			(1		)									—			238
	Other	3,094			$	12			(11		)		10			14			$	608							(267		)	3,460
	Total asset-backed securities	3,852			12				(47		)		12			18			608								(279		)	4,176
	Non-U.S. debt securities:
	Mortgage-backed securities	273			—				(147		)		—			—			156								3			285
	Asset-backed securities	1,362			—				(676		)		1			4			—								(14		)	677
Other	1			—				—				—			—			193								—			194
Total non-U.S. debt securities	1,636			—				(823		)		1			4			349								(11		)	1,156
State and political subdivisions	49			—				—				—			(1		)	—								—			48
Collateralized mortgage obligations	301			—				(123		)		168			1			—				$	(45	)		(178		)	124
Other U.S. debt securities	—			9				—				—			—			—				—				—			9
Total investment securities available for sale	6,771			21				(993		)		181			25			957				(45		)		(498		)	6,419
Other assets:
Derivative instruments, Foreign exchange contracts	160			—				—				(69		)	—			75				—				(67		)	99			$	(47	)
Total assets carried at fair value	$	6,931		$	21			$	(993	)		$	112		$	25		$	1,032	—		(45		)		$	(565	)	$	6,518		$	(47	)
The following tables present activity related to our level-3 financial assets and liabilities during the three and nine months ended September 30, 2013 and 2012, respectively. Transfers into and out of level 3 are reported as of the beginning of the period. In both the three and nine months ended September 30, 2013 and 2012, transfers out of level 3 were substantially related to certain asset-backed securities and non-U.S. debt securities, for which fair value was measured using prices for which observable market information became available.
	Fair-Value Measurements Using Significant Unobservable Inputs
	Three Months Ended September 30, 2013
	Fair			Transfers				Transfers				Total Realized and						Purchases		Issuances		Sales				Settlements			Fair Value as of			Change in
	Value as of			into				out of				Unrealized Gains (Losses)																	30-Sep-13			Unrealized
	June 30,			Level 3				Level 3																								Gains
	2013																															(Losses)
																																Related to
																																Financial
																																Instruments
																																Held as of
																																September 30,
(In millions)												Recorded			Recorded																	2013
												in			in Other
												Revenue			Comprehensive
															Income
Assets:
Investment securities available for sale:
U.S. Treasury and federal agencies, mortgage-backed securities	$	864						$	(93	)					$	(1	)									$	(29	)	$	741
Asset-backed securities:
Student loans	380							—							(2		)									(10		)	368
Credit cards	24							—							—											—			24
Other	3,848							—				$	13		(5		)	$	793			$	(24	)		(275		)	4,350
Total asset-backed securities	4,252							—				13			(7		)	793				(24		)		(285		)	4,742
Non-U.S. debt securities:
Mortgage-backed securities	328							—				—			(1		)	—				—				13			340
Asset-backed securities	756							(104		)		1			1			164				—				(19		)	799
Other	281							—				—			(1		)	149				—				12			441
Total non-U.S. debt securities	1,365							(104		)		1			(1		)	313				—				6			1,580
State and political subdivisions	45							—				—			(1		)	—								—			44
Collateralized mortgage obligations	238			$	15			(100		)		—			(5		)	50				—				(11		)	187
Other U.S. debt securities	9			—				—				—			—			—				—				—			9
Total investment securities available for sale	6,773			15				(297		)		14			(15		)	1,156				(24		)		(319		)	7,303
Other assets:
Derivative instruments, Foreign exchange contracts	121			—				—				(21		)	—			7				—				(30		)	77			$	(16	)
Total assets carried at fair value	$	6,894		$	15			$	(297	)		$	(7	)	$	(15	)	$	1,163	—		$	(24	)		$	(349	)	$	7,380		$	(16	)
	Fair-Value Measurements Using Significant Unobservable Inputs
	Nine Months Ended September 30, 2012
	Fair			Transfers				Transfers				Total Realized and						Purchases		Issuances		Sales				Settlements			Fair			Change in
	Value as of December 31,			into				out of				Unrealized Gains (Losses)																	Value as of			Unrealized
	2011			Level 3				Level 3																					September 30,			Gains
																													2012			(Losses)
																																Related to
																																Financial
																																Instruments
																																Held as of
																																September 30,
(In millions)												Recorded			Recorded																	2012
												in			in Other
												Revenue			Comprehensive
															Income
Assets:
Investment securities available for sale:
U.S. Treasury and federal agencies:
Mortgage-backed securities	$	1,189		$	50			$	(251	)					$	3										$	(85	)	$	906
Asset-backed securities:
Student loans	860			—				(341		)		$	2		(5		)									(38		)	478
Credit cards	91			21				(36		)		4			(5		)	$	224			$	(61	)		—			238
Other	2,798			12				(11		)		31			39			1,177				(12		)		(574		)	3,460
Total asset-backed securities	3,749			33				(388		)		37			29			1,401				(73		)		(612		)	4,176
Non-U.S. debt securities:
Mortgage-backed securities	1,457			—				(1,642		)		—			3			463				—				4			285
Asset-backed securities	1,768			—				(2,243		)		1			4			1,206				—				(59		)	677
Other	71			—				(372		)		—			(3		)	500				—				(2		)	194
Total non-U.S. debt securities	3,296			—				(4,257		)		1			4			2,169				—				(57		)	1,156
State and political subdivisions	50			—				—				—			—			—								(2		)	48
Collateralized mortgage obligations	227			44				(314		)		369			1			283				(45		)		(441		)	124
Other U.S. debt securities	2			9				—				—			—			—				—				(2		)	9
Total investment securities available for sale	8,513			136				(5,210		)		407			37			3,853				(118		)		(1,199		)	6,419
Other assets:
Derivative instruments:
Foreign exchange contracts	168			—				—				(127		)	—			162				—				(104		)	99			$	(71	)
Interest-rate contracts	10			—				—				(10		)	—			—				—				—			—			—
Total derivative instruments	178			—				—				(137		)	—			162				—				(104		)	99			(71		)
Total assets carried at fair value	$	8,691		$	136			$	(5,210	)		$	270		$	37		$	4,015	—		$	(118	)		$	(1,303	)	$	6,518		$	(71	)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	'
		Fair-Value Measurements Using Significant Unobservable Inputs
		Nine Months Ended September 30, 2013
		Fair			Transfers			Transfers			Total Realized and						Purchases		Issuances		Sales		Settlements				Fair			Change in
		Value as of			into			out of			Unrealized (Gains) Losses																Value as of			Unrealized
		December 31,			Level 3			Level 3																			September 30,			(Gains)
		2012																									2013			Losses
																														Related to
																														Financial
																														Instruments
																														Held as of
																														September 30,
	(In millions)										Recorded				Recorded															2013
											in				in Other
											Revenue				Comprehensive
															Income
	Liabilities:
	Accrued expenses and other liabilities:
	Derivative instruments:
	Foreign exchange contracts	$	106								$	59							$	24			$	(134	)		$	55		$	15
	Other	9									—								—				—				9			—
	Total derivative instruments	115									59								24				(134		)		64			15
	Total liabilities carried at fair value	$	115		—			—			$	59			—		—		$	24	—		$	(134	)		$	64		$	15
		Fair-Value Measurements Using Significant Unobservable Inputs
		Three Months Ended September 30, 2012
		Fair			Transfers			Transfers			Total Realized and						Purchases		Issuances		Sales		Settlements				Fair			Change in
		Value as of June 30,			into			out of			Unrealized (Gains) Losses																Value as of			Unrealized
		2012			Level 3			Level 3																			September 30,			(Gains)
																											2012			Losses
																														Related to
																														Financial
																														Instruments
																														Held as of
																														September 30,
	(In millions)										Recorded				Recorded															2012
											in				in Other
											Revenue				Comprehensive
															Income
	Liabilities:
	Accrued expenses and other liabilities:
	Derivative instruments:
	Foreign exchange contracts	$	157								$	(58	)						$	76			$	(75	)		$	100		$	(43	)
	Other	9									—								—				—				9			—
	Total derivative instruments	166									(58		)						76				(75		)		109			(43		)
	Total liabilities carried at fair value	$	166		—			—			$	(58	)		—		—		$	76	—		$	(75	)		$	109		$	(43	)
		Fair-Value Measurements Using Significant Unobservable Inputs
		Nine Months Ended September 30, 2012
		Fair			Transfers			Transfers			Total Realized and						Purchases		Issuances		Sales		Settlements				Fair			Change in
		Value as of December 31,			into			out of			Unrealized (Gains) Losses																Value as of			Unrealized
		2011			Level 3			Level 3																			September 30,			(Gains)
																											2012			Losses
																														Related to
																														Financial
																														Instruments
																														Held as of
																														September 30,
	(In millions)										Recorded				Recorded															2012
											in				in Other
											Revenue				Comprehensive
															Income
	Liabilities:
	Accrued expenses and other liabilities:
	Derivative instruments:
	Foreign exchange contracts	$	161								$	(131	)						$	162			$	(92	)		$	100		$	(70	)
Interest-rate contracts	11									(11		)						—				—				—			—
Other	9									—								—				—				9			—
Total derivative instruments	181									(142		)						162				(92		)		109			(70		)
Other	20									—								—				(20		)		—
Total liabilities carried at fair value	$	201		—			—			$	(142	)		—		—		$	162	—		$	(112	)		$	109		$	(70	)
	Fair-Value Measurements Using Significant Unobservable Inputs
	Three Months Ended September 30, 2013
	Fair			Transfers			Transfers			Total Realized and						Purchases		Issuances		Sales		Settlements				Fair Value as of			Change in
	Value as of			into			out of			Unrealized (Gains) Losses																30-Sep-13			Unrealized
	June 30,			Level 3			Level 3																						(Gains)
	2013																												Losses
																													Related to
																													Financial
																													Instruments
																													Held as of
																													September 30,
(In millions)										Recorded				Recorded															2013
										in				in Other
										Revenue				Comprehensive
														Income
Liabilities:
Accrued expenses and other liabilities:
Derivative instruments:
Foreign exchange contracts	$	108								$	(17	)						$	5			$	(41	)		$	55		$	(15	)
Other	9									—								—				—				9			—
Total derivative instruments	117									(17		)						5				(41		)		64			(15		)
Total liabilities carried at fair value	$	117		—			—			$	(17	)		—		—		$	5	—		$	(41	)		$	64		$	(15	)
Level 3 Total Realized And Unrealized Gains And Losses Recorded In Revenue	'
	The following table presents total realized and unrealized gains and losses, for the periods indicated, that were recorded in revenue for our level-3 financial assets and liabilities:
		Three Months Ended September 30,														Nine Months Ended September 30,
		Total Realized and							Change in							Total Realized and					Change in
		Unrealized Gains							Unrealized Gains							Unrealized Gains					Unrealized Gains
		(Losses) Recorded							(Losses) Related to							(Losses) Recorded					(Losses) Related to
		in Revenue							Financial							in Revenue					Financial
									Instruments Held as of												Instruments Held as of
									September 30,												September 30,
	(In millions)	2013			2012				2013				2012			2013			2012		2013			2012
	Fee revenue:
	Trading services	$	(4	)	$	(11	)		$	(1	)		$	(4	)	$	60		$	5	$	14		$	(1	)
	Total fee revenue	(4		)	(11		)		(1		)		(4		)	60			5		14			(1		)
	Net interest revenue	14			181				—				—			46			407		—			—
	Total revenue	$	10		$	170			$	(1	)		(4		)	$	106		$	412	$	14		$	(1	)
Fair Value Inputs, Assets and Liabilities, Quantitative Information	'
	The following table presents quantitative information, as of the dates indicated, about the valuation techniques and significant unobservable inputs used in the valuation of our level-3 financial assets and liabilities measured at fair value on a recurring basis for which we use internally-developed pricing models. The significant unobservable inputs for our level-3 financial assets and liabilities whose fair value is measured using pricing information from non-binding broker or dealer quotes are not included in the table, as the specific inputs applied are not provided by the broker/dealer.
			Quantitative Information about Level-3 Fair-Value Measurements
			Fair Value											Weighted-Average
	(Dollars in millions)		As of			As of				Valuation Technique		Significant		As of September 30, 2013		As of December 31, 2012
			30-Sep-13			31-Dec-12						Unobservable Input
	Significant unobservable inputs readily available to State Street:
	Assets:
	Asset-backed securities, student loans		$	13		$	12			Discounted cash flows		Credit spread		4.4	%	6.7	%
	Asset-backed securities, credit cards		24			67				Discounted cash flows		Credit spread		2.1		7.1
	Asset-backed securities, other		101			103				Discounted cash flows		Credit spread		1		1.5
	State and political subdivisions		44			48				Discounted cash flows		Credit spread		2		1.9
	Derivative instruments, foreign exchange contracts		77			113				Option model		Volatility		13.3		9.8
	Total		$	259		$	343
	Liabilities:
	Derivative instruments, foreign exchange contracts		$	55		$	106			Option model		Volatility		13.1		9.8
	Derivative instruments, other		9			9				Discounted cash flows		Participant redemptions		7.1		6.7
	Total		$	64		$	115
Schedule of Availability of Significant Unobservable Inputs by Balance Sheet Classification	'
	The following tables present information with respect to the composition of our level-3 financial assets and liabilities, by availability of significant unobservable inputs, as of the dates indicated:
	30-Sep-13		Significant Unobservable Inputs Readily Available to State Street(1)			Significant Unobservable Inputs Not Developed by State Street and Not Readily Available(2)				Total Assets and Liabilities with Significant Unobservable Inputs
	(In millions)
	Assets:
	U.S. Treasury and federal agencies, mortgage-backed securities		$	—		$	741			$	741
	Asset-backed securities, student loans		13			355				368
	Asset-backed securities, credit cards		24			—				24
	Asset-backed securities, other		101			4,249				4,350
	Non-U.S. debt securities, mortgage-backed securities		—			340				340
	Non-U.S. debt securities, asset-backed securities		—			799				799
	Non-U.S. debt securities, other		—			441				441
	State and political subdivisions		44			—				44
	Collateralized mortgage obligations		—			187				187
	Other U.S.debt securities		—			9				9
	Derivative instruments, foreign exchange contracts		77			—				77
	Total		$	259		$	7,121			$	7,380
	Liabilities:
	Derivative instruments, foreign exchange contracts		$	55		—				$	55
	Derivative instruments, other		9			—				9
	Total		$	64		—				$	64
	31-Dec-12		Significant Unobservable Inputs Readily Available to State Street(1)			Significant Unobservable Inputs Not Developed by State Street and Not Readily Available(2)				Total Assets and Liabilities with Significant Unobservable Inputs
	(In millions)
	Assets:
	U.S. Treasury and federal agencies, mortgage-backed securities		$	—		$	825			$	825
	Asset-backed securities, student loans		12			576				588
	Asset-backed securities, credit cards		67			—				67
	Asset-backed securities, other		103			3,891				3,994
	Non-U.S. debt securities, mortgage-backed securities		—			555				555
	Non-U.S. debt securities, asset-backed securities		—			524				524
	Non-U.S. debt securities, other		—			140				140
	State and political subdivisions		48			—				48
	Collateralized mortgage obligations		—			117				117
	Other U.S.debt securities		—			9				9
	Derivative instruments, foreign exchange contracts		113			—				113
	Total		$	343		$	6,637			$	6,980
	Liabilities:
	Derivative instruments, foreign exchange contracts		$	106		—				$	106
	Derivative instruments, other		9			—				9
	Total		$	115		—				$	115
	(1) Information with respect to these model-priced financial assets and liabilities is provided in the preceding table.
	(2) Fair value for these financial assets is measured using non-binding broker or dealer quotes.
Carrying Value and Estimated Fair Value of Financial Instruments by Fair Value Hierarchy	'
	The following tables present the reported amounts and estimated fair values of the financial instruments defined by GAAP, excluding financial assets and liabilities carried at fair value on a recurring basis, as they would be categorized within the fair-value hierarchy, as of the dates indicated.
										Fair-Value Hierarchy
	30-Sep-13		Reported Amount			Estimated Fair Value				Quoted Market Prices in Active Markets (Level 1)				Pricing Methods with Significant Observable Market Inputs (Level 2)			Pricing Methods with Significant Unobservable Market Inputs (Level 3)
	(In millions)
	Financial Assets:
	Cash and due from banks		$	3,896		$	3,896			$	3,896			$	—		$	—
	Interest-bearing deposits with banks		38,636			38,636				—				38,636			—
	Securities purchased under resale agreements		5,827			5,827				—				5,827			—
	Investment securities held to maturity		16,698			16,543				—				16,543			—
	Loans (excluding leases)		14,445			14,431				—				13,968			463
	Financial Liabilities:
	Deposits:
	Noninterest-bearing		$	45,679		$	45,679			$	—			$	45,679		$	—
	Interest-bearing - U.S.		6,575			6,575				—				6,575			—
	Interest-bearing - non-U.S.		101,945			101,945				—				101,945			—
	Securities sold under repurchase agreements		10,123			10,123				—				10,123			—
	Federal funds purchased		94			94				—				94			—
	Other short-term borrowings		3,657			3,657				—				3,657			—
	Long-term debt		8,748			9,101				—				8,125			976
										Fair-Value Hierarchy
	31-Dec-12		Reported Amount			Estimated Fair Value				Quoted Market Prices in Active Markets (Level 1)				Pricing Methods with Significant Observable Market Inputs (Level 2)			Pricing Methods with Significant Unobservable Market Inputs (Level 3)
	(In millions)
	Financial Assets:
	Cash and due from banks		$	2,590		$	2,590			$	2,590			$	—		$	—
	Interest-bearing deposits with banks		50,763			50,763				—				50,763			—
	Securities purchased under resale agreements		5,016			5,016				—				5,016			—
	Investment securities held to maturity		11,379			11,661				—				11,661			—
	Loans (excluding leases)		11,121			11,166				—				10,276			890
	Financial Liabilities:
	Deposits:
	Noninterest-bearing		$	44,445		$	44,445			$	—			$	44,445		$	—
	Interest-bearing - U.S.		19,201			19,201				—				19,201			—
	Interest-bearing - non-U.S.		100,535			100,535				—				100,535			—
	Securities sold under repurchase agreements		8,006			8,006				—				8,006			—
	Federal funds purchased		399			399				—				399			—
	Other short-term borrowings		4,502			4,502				—				4,502			—
	Long-term debt		7,429			7,780				—				6,871			909

Investment_Securities_Tables

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Schedule of Marketable Securities	'
	The following table presents the amortized cost and fair value, and associated unrealized gains and losses, of investment securities as of the dates indicated:
		September 30, 2013												December 31, 2012
		Amortized			Gross						Fair			Amortized		Gross				Fair
		Cost			Unrealized						Value			Cost		Unrealized				Value
	(In millions)				Gains			Losses								Gains		Losses
	Available for sale:
	U.S. Treasury and federal agencies:
	Direct obligations	$	729		$	11		$	2		$	738		$	823	$	19	$	1	$	841
	Mortgage-backed securities	24,562			275			262			24,575			31,640		598		26		32,212
	Asset-backed securities:
	Student loans(1)	15,079			94			302			14,871			16,829		100		508		16,421
	Credit cards	8,649			23			46			8,626			9,928		61		3		9,986
	Sub-prime	1,371			5			110			1,266			1,557		4		162		1,399
	Other	4,772			148			19			4,901			4,583		155		61		4,677
	Total asset-backed securities	29,871			270			477			29,664			32,897		320		734		32,483
	Non-U.S. debt securities:
	Mortgage-backed securities	10,773			241			13			11,001			11,119		313		27		11,405
	Asset-backed securities	5,445			25			3			5,467			6,180		42		4		6,218
	Government securities	3,537			4			—			3,541			3,197		2		—		3,199
	Other	4,556			58			14			4,600			4,221		86		1		4,306
	Total non-U.S. debt securities	24,311			328			30			24,609			24,717		443		32		25,128
	State and political subdivisions	9,307			171			180			9,298			7,384		234		67		7,551
	Collateralized mortgage obligations	5,152			79			73			5,158			4,818		151		15		4,954
	Other U.S. debt securities	4,925			153			33			5,045			5,072		233		7		5,298
	U.S. equity securities	34			5			—			39			28		3		—		31
	Non-U.S. equity securities	2			—			—			2			1		—		—		1
	U.S. money-market mutual funds	680			—			—			680			1,062		—		—		1,062
	Non-U.S. money-market mutual funds	174			—			—			174			121		—		—		121
	Total	$	99,747		$	1,292		$	1,057		$	99,982		$	108,563	$	2,001	$	882	$	109,682
	Held to maturity:
	U.S. Treasury and federal agencies:
	Direct obligations	$	5,003		$	—		$	390		$	4,613		$	5,000	$	—	$	8	$	4,992
	Mortgage-backed securities	100			7			—			107			153		11		—		164
	Asset-backed securities:
	Student loans(1)	1,502			—			11			1,491			—		—		—		—
	Credit cards	531			—			—			531			—		—		—		—
	Other	818			—			3			815			16		—		—		16
	Total asset-backed securities	2,851			—			14			2,837			16		—		—		16
	Non-U.S. debt securities:
	Mortgage-backed securities	4,109			130			67			4,172			3,122		85		68		3,139
	Asset-backed securities	1,486			18			2			1,502			434		16		1		449
	Government securities	16			—			—			16			3		—		—		3
	Other	190			—			—			190			167		—		2		165
	Total non-U.S. debt securities	5,801			148			69			5,880			3,726		101		71		3,756
	State and political subdivisions	61			1			—			62			74		2		—		76
	Collateralized mortgage obligations	2,882			193			31			3,044			2,410		259		12		2,657
	Total	$	16,698		$	349		$	504		$	16,543		$	11,379	$	373	$	91	$	11,661
	(1) Substantially composed of securities guaranteed by the federal government with respect to at least 97% of defaulted principal and
	accrued interest on the underlying loans.
Schedule of Gross Pre-tax Unrealized Losses on Investment Securities	'
	The following tables present the aggregate fair values of investment securities that have been in a continuous unrealized loss position for less than 12 months, and those that have been in a continuous unrealized loss position for 12 months or longer, as of the dates indicated:
		Less than 12 months						12 months or longer						Total
	September 30, 2013	Fair			Gross			Fair			Gross			Fair		Gross
		Value			Unrealized			Value			Unrealized			Value		Unrealized
	(In millions)				Losses						Losses					Losses
	Available for sale:
	U.S. Treasury and federal agencies:
	Direct obligations	$	158		$	1		$	117		$	1		$	275	$	2
	Mortgage-backed securities	9,721			232			1,933			30			11,654		262
	Asset-backed securities:
	Student loans	2,123			19			7,463			283			9,586		302
	Credit cards	3,734			46			—			—			3,734		46
	Sub-prime	16			1			1,193			109			1,209		110
	Other	896			5			469			14			1,365		19
	Total asset-backed securities	6,769			71			9,125			406			15,894		477
	Non-U.S. debt securities:
	Mortgage-backed securities	1,240			3			242			10			1,482		13
	Asset-backed securities	708			1			21			2			729		3
	Other	1,434			14			—			—			1,434		14
	Total non-U.S. debt securities	3,382			18			263			12			3,645		30
	State and political subdivisions	2,436			118			1,080			62			3,516		180
	Collateralized mortgage obligations	1,665			65			304			8			1,969		73
	Other U.S. debt securities	1,047			27			33			6			1,080		33
	Total	$	25,178		$	532		$	12,855		$	525		$	38,033	$	1,057
	Held to maturity:
	U.S. Treasury and federal agencies:
	Direct obligations	$	4,611		$	390		$	—		$	—		$	4,611	$	390
	Asset-backed securities:
	Student loans	1,234			11			—			—			1,234		11
	Other	580			3			—			—			580		3
	Total asset-backed securities	1,814			14			—			—			1,814		14
	Non-U.S. debt securities:
	Mortgage-backed securities	1,155			5			893			62			2,048		67
	Asset-backed securities	717			2			—			—			717		2
	Total non-U.S. debt securities	1,872			7			893			62			2,765		69
	Collateralized mortgage obligations	905			27			96			4			1,001		31
	Total	$	9,202		$	438		$	989		$	66		$	10,191	$	504
		Less than 12 months						12 months or longer						Total
	December 31, 2012	Fair			Gross			Fair			Gross			Fair		Gross
		Value			Unrealized			Value			Unrealized			Value		Unrealized
	(In millions)				Losses						Losses					Losses
	Available for sale:
	U.S. Treasury and federal agencies:
	Direct obligations	$	—		$	—		$	132		$	1		$	132	$	1
	Mortgage-backed securities	3,486			18			865			8			4,351		26
	Asset-backed securities:
	Student loans	625			6			10,241			502			10,866		508
	Credit cards	888			3			—			—			888		3
	Sub-prime	—			—			1,346			162			1,346		162
	Other	639			13			989			48			1,628		61
	Total asset-backed securities	2,152			22			12,576			712			14,728		734
	Non-U.S. debt securities:
	Mortgage-backed securities	670			3			453			24			1,123		27
	Asset-backed securities	973			1			53			3			1,026		4
	Other	509			1			—			—			509		1
	Total non-U.S. debt securities	2,152			5			506			27			2,658		32
	State and political subdivisions	685			9			1,152			58			1,837		67
	Collateralized mortgage obligations	347			1			621			14			968		15
	Other U.S. debt securities	302			1			33			6			335		7
	Total	$	9,124		$	56		$	15,885		$	826		$	25,009	$	882
	Held to maturity:
	U.S. Treasury and federal agencies:
	Direct obligations	$	3,792		$	8		$	—		$	—		$	3,792	$	8
Non-U.S. debt securities:
Mortgage-backed securities	56			1			956			67			1,012		68
Asset-backed securities	—			—			73			1			73		1
Other	—			—			156			2			156		2
Total non-U.S. debt securities	56			1			1,185			70			1,241		71
Collateralized mortgage obligations	120			1			153			11			273		12
Total	$	3,968		$	10		$	1,338		$	81		$	5,306	$	91
Investments Classified by Contractual Maturity Date	'
	The following table presents contractual maturities of debt investment securities as of September 30, 2013:
	(In millions)	Under 1			1 to 5			6 to 10			Over 10
		Year			Years			Years			Years
	Available for sale:
	U.S. Treasury and federal agencies:
	Direct obligations	$	—		$	42		$	46		$	650
	Mortgage-backed securities	103			1,847			6,188			16,437
	Asset-backed securities:
	Student loans	1,019			6,513			4,646			2,693
	Credit cards	2,919			3,506			2,201			—
	Sub-prime	26			28			2			1,210
	Other	341			1,758			1,432			1,370
	Total asset-backed securities	4,305			11,805			8,281			5,273
	Non-U.S. debt securities:
	Mortgage-backed securities	148			6,191			159			4,503
	Asset-backed securities	253			4,685			378			151
	Government securities	2,541			1,000			—			—
	Other	1,143			2,912			545			—
	Total non-U.S. debt securities	4,085			14,788			1,082			4,654
	State and political subdivisions	668			3,059			3,565			2,006
	Collateralized mortgage obligations	271			1,923			1,157			1,807
	Other U.S. debt securities	215			4,094			703			33
	Total	$	9,647		$	37,558		$	21,022		$	30,860
	Held to maturity:
	U.S. Treasury and federal agencies:
	Direct obligations	$	—		$	—		$	5,000		$	3
	Mortgage-backed securities	—			25			19			56
	Asset-backed securities
	Student loans	19			153			219			1,111
	Credit cards	—			229			302			—
	Other	—			510			302			6
	Total asset-backed securities	19			892			823			1,117
	Non-U.S. debt securities:
	Mortgage-backed securities	—			939			164			3,006
	Asset-backed securities	80			1,235			171			—
	Government securities	16			—			—			—
	Other	162			24			—			4
	Total non-U.S. debt securities	258			2,198			335			3,010
	State and political subdivisions	48			13			—			—
	Collateralized mortgage obligations	102			1,174			502			1,104
	Total	$	427		$	4,302		$	6,679		$	5,290
Gains and Losses Related to Investment Securities	'
	The following table presents gross realized gains and gross realized losses from sales of available-for-sale securities and the components of net impairment losses, included in net gains and losses related to investment securities, for the periods indicated:
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Gross realized gains from sales of available-for-sale securities	$	11		$	24		$	98		$	75
	Gross realized losses from sales of available-for-sale securities(1)	(5		)	—			(87		)	(46		)
	Gross losses from other-than-temporary impairment	(8		)	(4		)	(8		)	(50		)
	Losses reclassified (from) to other comprehensive income	(2		)	(2		)	(12		)	23
	Net impairment losses recognized in consolidated statement of income	(10		)	(6		)	(20		)	(27		)
	Gains (losses) related to investment securities, net	$	(4	)	$	18		$	(9	)	$	2
	Impairment associated with expected credit losses	$	(8	)	$	(1	)	$	(8	)	$	(14	)
	Impairment associated with management's intent to sell impaired securities prior to recovery in value	—			—			(6		)	—
	Impairment associated with adverse changes in timing of expected future cash flows	(2		)	(5		)	(6		)	(13		)
	Net impairment losses recognized in consolidated statement of income	$	(10	)	$	(6	)	$	(20	)	$	(27	)
	(1) Amount for the nine months ended September 30, 2012 represented a pre-tax loss from the sale of all of our Greek investment securities, which had an aggregate carrying value of approximately $91 million.
Schedule of Credit-Related Loss Activity Recognized in Earnings	'
	The following table presents activity with respect to net impairment losses for the periods indicated:
		Nine Months Ended September 30,
	(In millions)	2013			2012
	Beginning balance	$	124		$	113
	Plus losses for which other-than-temporary impairment was not previously recognized	14			2
	Plus losses for which other-than-temporary impairment was previously recognized	6			25
	Less previously recognized losses related to securities sold or matured	(10		)	(21		)
	Ending balance	$	134		$	119

Loans_and_Leases_Tables

Loans and Leases (Tables)	9 Months Ended
	Sep. 30, 2013
Loans and Leases Receivable Disclosure [Abstract]	'
Net Loans	'
	The following table presents our recorded investment in loans and leases, by segment and class, as of the dates indicated:
	(In millions)	September 30, 2013			December 31, 2012
	Institutional:
	Investment funds:
	U.S.	$	10,017		$	8,376
	Non-U.S.	1,998			829
	Commercial and financial:
	U.S.	1,486			613
	Non-U.S.	509			520
	Purchased receivables:
	U.S.	231			276
	Non-U.S.	60			118
	Lease financing:
	U.S.	357			380
	Non-U.S.	754			784
	Total institutional	15,412			11,896
	Commercial real estate:
	U.S.	166			411
	Total loans and leases	15,578			12,307
	Allowance for loan losses	(22		)	(22		)
	Loans and leases, net of allowance for loan losses	$	15,556		$	12,285
Recorded Investment in Each Class of Total Loans and Leases by Credit Quality Indicator	'
	The following tables present our recorded investment in each class of loans and leases by credit quality indicator as of the dates indicated:
		Institutional										Commercial Real Estate
	September 30, 2013	Investment			Commercial and Financial			Purchased		Lease		Property Development			Other			Total
		Funds						Receivables		Financing								Loans and
	(In millions)																	Leases
	Investment grade(1)	$	11,574		$	1,456		$	291	$	1,079	$	—		$	29		$	14,429
	Speculative(2)	441			519			—		32		137			—			1,129
	Special mention(3)	—			20			—		—		—			—			20
	Total	$	12,015		$	1,995		$	291	$	1,111	$	137		$	29		$	15,578
		Institutional										Commercial Real Estate
	December 31, 2012	Investment			Commercial and Financial			Purchased		Lease		Property Development			Other			Total
		Funds						Receivables		Financing								Loans and
	(In millions)																	Leases
	Investment grade(1)	$	8,937		$	1,041		$	394	$	1,137	$	—		$	29		$	11,538
	Speculative(2)	268			92			—		27		377			5			769
	Total	$	9,205		$	1,133		$	394	$	1,164	$	377		$	34		$	12,307
	( 1) Investment grade loans and leases consist of counterparties with strong credit quality and low expected credit risk and probability of default. Ratings apply to counterparties with a strong capacity to support the timely repayment of any financial commitment.
	(2) Speculative loans and leases consist of counterparties that face ongoing uncertainties or exposure to business, financial, or economic downturns. However, these counterparties may have financial flexibility or access to financial alternatives, which allow for financial commitments to be met.
	(3) Special mention loans and leases consist of counterparties with potential weaknesses that, if uncorrected, may result in deterioration of repayment prospects.
Schedule of Loans and Leases Receivable by Impairment Methodology	'
	The following table presents our recorded investment in loans and leases, disaggregated based on our impairment methodology, as of the dates indicated:
		September 30, 2013								December 31, 2012
	(In millions)	Institutional			Commercial Real Estate			Total Loans and Leases		Institutional		Commercial Real Estate			Total Loans and Leases
	Loans and leases:
	Individually evaluated for impairment	$	405		$	137		$	542	$	11	$	411		$	422
	Collectively evaluated for impairment(1)	15,007			29			15,036		11,885		—			11,885
	Total	$	15,412		$	166		$	15,578	$	11,896	$	411		$	12,307
	(1) As of both September 30, 2013 and December 31, 2012, the entire $22 million allowance for loan losses was related to institutional loans collectively evaluated for impairment.
Impaired Loans	'
	The following tables present information related to our recorded investment in impaired loans and leases as of the dates, or for the periods, indicated:
		September 30, 2013								December 31, 2012
	(In millions)	Recorded Investment			Unpaid			Related Allowance(1)		Recorded Investment		Unpaid			Related Allowance(1)
					Principal							Principal
					Balance							Balance
	With no related allowance recorded:
	CRE—property development	$	130		$	143		$	—	$	197	$	224		$	—
	CRE—property development—acquired credit-impaired	—			34			—		—		34			—
	CRE—other—acquired credit-impaired	—			21			—		—		64			—
	Total CRE	$	130		$	198		$	—	$	197	$	322		$	—
	(1) As of both September 30, 2013 and December 31, 2012, we maintained an allowance for loan losses of $22 million associated with loans and leases that were not impaired.
		Three Months Ended September 30,										Nine Months Ended September 30,
		Average Recorded Investment						Interest Revenue Recognized				Average Recorded Investment						Interest Revenue Recognized
	(In millions)	2013			2012			2013		2012		2013			2012			2013		2012
	With no related allowance recorded:
	CRE—property development	$	130		$	199		$	2	$	4	$	160		$	199		$	17	$	12
	CRE—other—acquired credit-impaired	—			5			—		—		—			17			—		—
	With an allowance recorded:
	CRE—other—acquired credit-impaired	—			—			—		—		—			—			—		—
	Total CRE	$	130		$	204		$	2	$	4	$	160		$	216		$	17	$	12
Schedule of Activity in the Allowance for Loan Losses	'
	The following table presents activity in the allowance for loan losses for the periods indicated:
		Three Months Ended September 30,
		2013								2012
	(In millions)	Institutional			Commercial			Total Loans and Leases		Institutional		Commercial			Total Loans
					Real Estate							Real Estate			and Leases
	Allowance for loan losses:
	Beginning balance	$	22		$	—		$	22	$	22	$	—		$	22
	Provisions	—			—			—		—		—			—
	Recoveries	—			—			—		—		—			—
	Ending balance	$	22		$	—		$	22	$	22	$	—		$	22
		Nine Months Ended September 30,
		2013								2012
	(In millions)	Institutional			Commercial			Total Loans and Leases		Institutional		Commercial			Total Loans
					Real Estate							Real Estate			and Leases
	Allowance for loan losses:
	Beginning balance	$	22		$	—		$	22	$	22	$	—		$	22
	Provisions	—			—			—		—		(1		)	(1		)
	Recoveries	—			—			—		—		1			1
	Ending balance	$	22		$	—		$	22	$	22	$	—		$	22

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Changes In The Carrying Amount Of Goodwill	'
	The following table presents changes in the carrying amount of goodwill during the periods indicated:
		Nine Months Ended September 30,
		2013									2012
	(In millions)	Investment			Investment			Total			Investment			Investment			Total
		Servicing			Management						Servicing			Management
	Beginning balance	$	5,941		$	36		$	5,977		$	5,610		$	35		$	5,645
	Divestitures	(7		)	—			(7		)	—			—			—
	Foreign currency translation, net	35			1			36			5			—			5
	Ending balance	$	5,969		$	37		$	6,006		$	5,615		$	35		$	5,650
Changes In The Carrying Amount Of Other Intangible Assets	'
	The following table presents changes in the net carrying amount of other intangible assets during the periods indicated:
		Nine Months Ended September 30,
		2013									2012
	(In millions)	Investment			Investment			Total			Investment			Investment			Total
		Servicing			Management						Servicing			Management
	Beginning balance	$	2,492		$	47		$	2,539		$	2,408		$	51		$	2,459
	Divestitures	(5		)	—			(5		)	—			—			—
	Amortization	(153		)	(7		)	(160		)	(143		)	(2		)	(145		)
	Foreign currency translation, net	22			—			22			(3		)	—			(3		)
	Ending balance	$	2,356		$	40		$	2,396		$	2,262		$	49		$	2,311
Schedule of Finite-Lived Intangible Assets	'
	The following table presents the gross carrying amount, accumulated amortization and net carrying amount of other intangible assets by type as of the dates indicated:
		September 30, 2013									December 31, 2012
	(In millions)	Gross			Accumulated			Net			Gross			Accumulated			Net
		Carrying			Amortization			Carrying			Carrying			Amortization			Carrying
		Amount						Amount			Amount						Amount
	Client relationships	$	2,669		$	(917	)	$	1,752		$	2,653		$	(755	)	$	1,898
	Core deposits	712			(180		)	532			706			(192		)	514
	Other	248			(136		)	112			244			(117		)	127
	Total	$	3,629		$	(1,233	)	$	2,396		$	3,603		$	(1,064	)	$	2,539

Other_Assets_and_Other_Liabili1

Other Assets and Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2013
Other Assets [Abstract]	'
Components of Other Assets	'
	The following table presents the components of other assets as of the dates indicated:
	(In millions)	September 30, 2013		December 31, 2012
	Collateral deposits, net	$	12,106	$	7,649
	Unrealized gains on derivative financial instruments, net	4,320		4,556
	Bank-owned life insurance	2,027		2,000
	Investments in joint ventures and other unconsolidated entities	1,466		1,405
	Accounts receivable	1,109		511
	Receivable for securities settlement	358		33
	Deferred tax assets, net of valuation allowance	302		353
	Prepaid expenses	299		267
	Income taxes receivable	261		252
	Deposits with clearing organizations	179		174
	Receivable for securities sold	92		1
	Other(1)	838		815
	Total	$	23,357	$	18,016
	(1)	Included other real estate owned of approximately $58 million and $65 million, respectively.

Commitments_Guarantees_and_Con1

Commitments, Guarantees, and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of Guarantor Obligations	'
	The following table presents the aggregate gross contractual amounts of off-balance sheet guarantees as of the dates indicated. Amounts presented do not reflect participations to independent third parties.
	(In millions)	September 30, 2013		December 31, 2012
	Indemnified securities financing	$	315,632	$	302,341
	Stable value protection	27,913		33,512
	Asset purchase agreements	4,646		5,063
	Standby letters of credit	4,601		4,552
Schedule of Repurchase Agreements	'
	The following table summarizes the fair values of indemnified securities financing and related collateral, as well as collateral invested in indemnified repurchase agreements, as of the dates indicated:
	(In millions)	September 30, 2013		December 31, 2012
	Aggregate fair value of indemnified securities financing	$	315,632	$	302,341
	Aggregate fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing	327,567		312,223
	Aggregate fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements	86,461		80,224
	Aggregate fair value of cash and securities held by us or our agents as collateral for investments in indemnified repurchase agreements	91,884		85,411

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Stockholders' Equity Note [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss)	'
	The following table presents the after-tax components of accumulated other comprehensive income (loss), or AOCI, as of the dates indicated:
	(In millions)	September 30, 2013			December 31, 2012
	Net unrealized gains on cash flow hedges	$	130		$	69
	Net unrealized gains on available-for-sale securities portfolio	138			815
	Net unrealized losses related to reclassified available-for-sale securities	(81		)	(110		)
	Net unrealized gains on available-for-sale securities	57			705
	Net unrealized losses on available-for-sale securities designated in fair value hedges	(122		)	(183		)
	Other-than-temporary impairment on available-for-sale securities related to factors other than credit	3			(3		)
	Net unrealized losses on hedges of net investments in non-U.S. subsidiaries	(14		)	(14		)
	Other-than-temporary impairment on held-to-maturity securities related to factors other than credit	(51		)	(65		)
	Net unrealized losses on retirement plans	(274		)	(283		)
	Foreign currency translation	157			134
	Total	$	(114	)	$	360
Schedule of Changes In Accumulated Other Comprehensive Income (Loss)	'
	The following table presents changes in AOCI by component, net of related taxes, in the nine months ended September 30:
		Nine Months Ended September 30, 2013
	(In millions)	Net Unrealized Gains (Losses) on Cash Flow Hedges			Net Unrealized Gains (Losses) on Available-for-Sale Securities			Net Unrealized Losses on Hedges of Net Investments in Non-U.S. Subsidiaries			Other-Than-Temporary Impairment on Held-to-Maturity Securities			Net Unrealized Losses on Retirement Plans			Foreign Currency Translation		Total
	Beginning balance	$	69		$	519		$	(14	)	$	(65	)	$	(283	)	$	134	$	360
	Other comprehensive income (loss) before reclassifications	59			(578		)	—			11			(6		)	22		(492		)
	Amounts reclassified out of AOCI	2			(3		)	—			3			15			1		18
	Other comprehensive income (loss)	61			(581		)	—			14			9			23		(474		)
	Ending balance	$	130		$	(62	)	$	(14	)	$	(51	)	$	(274	)	$	157	$	(114	)
Schedule of Reclassifications Out of AOCI	'
	The following table presents reclassifications out of AOCI in the three and nine months ended September 30, 2013:
		Amount Reclassified out of AOCI						Affected Line Item in Consolidated Statement of Income
	(In millions)	Three Months Ended September 30, 2013			Nine Months Ended September 30, 2013
	Cash flow hedges:
	Interest-rate contracts, net of related taxes of $1	$	—		$	2		Net interest revenue
	Available-for-sale securities:
	Net realized gains from sales of available-for-sale securities, net of related taxes of ($2) and ($4), respectively	(4		)	(7		)	Net gains (losses) from sales of available-for-sale securities
	Other-than-temporary impairment on available-for-sale securities related to factors other than credit, net of related taxes of $2	—			4			Losses reclassified (from) to other comprehensive income
	Held-to-maturity securities:
	Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, net of related taxes of $1 and $3, respectively	1			3			Losses reclassified (from) to other comprehensive income
	Retirement plans:
	Amortization of actuarial losses, net of related taxes of $3 and $9, respectively	5			15			Compensation and employee benefits expense
	Foreign currency translation:
	Sale of foreign entities, net of related taxes of $1	—			1			Processing fees and other revenue
	Total reclassifications out of AOCI	$	2		$	18

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Outstanding Hedges: (Notional Amount)	'
	The following table presents the aggregate contractual, or notional, amounts of derivative financial instruments entered into in connection with our trading and asset-and-liability management activities as of the dates indicated:
	(In millions)	September 30,				December 31,
		2013				2012
	Derivatives not designated as hedging instruments:
	Interest-rate contracts:
	Swap agreements and forwards	$	1,112			$	1,578
	Options and caps purchased	36				68
	Options and caps written	36				68
	Futures	5,126				1,910
	Foreign exchange contracts:
	Forward, swap and spot	1,118,507				897,354
	Options purchased	2,797				9,454
	Options written	2,357				8,734
	Credit derivative contracts:
	Credit swap agreements	136				27
	Other:
	Stable value contracts	27,913				33,512
	Futures	3				—
	Derivatives designated as hedging instruments:
	Interest-rate contracts:
	Swap agreements	4,222				3,153
	Foreign exchange contracts:
	Forward and swap	2,987				3,477
Notional Amount of Interest Rate Swap Agreements Designated as Fair Value and Cash Flow Hedges	'
	The following table presents the aggregate notional amounts of these interest-rate contracts and the related assets or liabilities being hedged as of the dates indicated:
		September 30, 2013												December 31, 2012
	(In millions)	Fair				Cash				Total				Fair				Cash				Total
		Value				Flow								Value				Flow
		Hedges				Hedges								Hedges				Hedges
	Investment securities available for sale	$	2,592			$	130			$	2,722			$	1,573			$	130			$	1,703
	Long-term debt(1)	1,500				—				1,500				1,450				—				1,450
	Total	$	4,092			$	130			$	4,222			$	3,023			$	130			$	3,153
	(1) As of September 30, 2013 and December 31, 2012, fair value hedges of long-term debt increased the carrying value of long-term debt presented in our consolidated statement of condition by $18 million and $174 million, respectively.
Contractual and Weighted-Average Interest Rates, Which Include the Effects of Hedges Related to Financial Instruments	'
	The following table presents the contractual and weighted-average interest rates for long-term debt, which include the effects of the hedges presented in the table above, for the periods indicated:
		Three Months Ended September 30,
		2013						2012
		Contractual			Rate Including			Contractual			Rate Including
		Rates			Impact of Hedges			Rates			Impact of Hedges
	Long-term debt	3.34	%		2.67	%		4.13	%		3.2	%
		Nine Months Ended September 30,
		2013						2012
		Contractual			Rate Including			Contractual			Rate Including
		Rates			Impact of Hedges			Rates			Impact of Hedges
	Long-term debt	3.49	%		2.77	%		4.01	%		3.2	%
Schedule of the Fair Values of Derivative Financial Instruments	'
	The following tables present the fair value of derivative financial instruments, excluding the impact of master netting agreements, recorded in our consolidated statement of condition as of the dates indicated. The impact of master netting agreements is disclosed in note 2.
		Asset Derivatives
		Balance Sheet		Fair Value
		Location
	(In millions)			September 30, 2013				December 31, 2012
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts	Other assets		$	10,109			$	9,243
	Interest-rate contracts	Other assets		34				61
	Credit derivative contracts	Other assets		1				—
	Total			$	10,144			$	9,304
	Derivatives designated as hedging instruments:
	Foreign exchange contracts	Other assets		$	257			$	135
	Interest-rate contracts	Other assets		24				162
	Total			$	281			$	297
		Liability Derivatives
		Balance Sheet		Fair Value
		Location
	(In millions)			September 30, 2013				December 31, 2012
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts	Other liabilities		$	10,210			$	9,067
	Interest-rate contracts	Other liabilities		35				61
	Other derivative contracts	Other liabilities		9				9
	Total			$	10,254			$	9,137
	Derivatives designated as hedging instruments:
	Interest-rate contracts	Other liabilities		$	272			$	284
	Foreign exchange contracts	Other liabilities		51				17
	Total			$	323			$	301
Impact of Derivatives on Consolidated Statement of Income	'
	The following tables present the impact of our use of derivative financial instruments on our consolidated statement of income for the periods indicated:
		Location of Gain (Loss) on		Amount of Gain (Loss) on Derivative Recognized in
		Derivative in Consolidated		Consolidated Statement
		Statement of Income		of Income
				Three Months Ended								Nine Months Ended
	(In millions)			September 30, 2013				September 30, 2012				September 30, 2013				September 30, 2012
	Derivatives not designated as hedging instruments:
	Foreign exchange contracts	Trading services revenue		$	147			$	113			$	461			$	459
	Foreign exchange contracts	Processing fees and other revenue		—				1				—				(2		)
	Interest-rate contracts	Trading services revenue		—				1				3				(87		)
	Interest-rate contracts	Processing fees and other revenue		—				—				—				2
	Credit derivative contracts	Processing fees and other revenue		1				—				1				—
	Total			$	148			$	115			$	465			$	372
Schedule of Differences Between the Gains (Losses) on the Derivative and the Gains (Losses) on the Hedged Item	'
		Location of Gain (Loss) on Derivative in Consolidated Statement of Income		Amount of Gain								Hedged Item in Fair Value Hedging Relationship		Location of Gain (Loss) on Hedged Item in Consolidated Statement of Income		Amount of Gain
				(Loss) on Derivative												(Loss) on Hedged
				Recognized  in												Item Recognized in
				Consolidated												Consolidated
				Statement of Income												Statement of Income
				Three Months Ended September 30, 2013				Nine Months Ended September 30, 2013								Three Months Ended September 30, 2013				Nine Months Ended September 30, 2013
	(In millions)
	Derivatives designated as fair value hedges:
	Foreign exchange contracts	Processing fees and		$	20			$	(135	)		Investment securities		Processing fees and		$	(20	)		$	135
		other revenue												other revenue
	Interest-rate contracts	Processing fees and		(14		)		(146		)		Long-term debt		Processing fees and		12				133
		other revenue												other revenue
	Interest-rate contracts	Processing fees and		(6		)		15				Available-for-sale securities		Processing fees and		7				(15		)
		other revenue												other revenue
	Total			$	—			$	(266	)						$	(1	)		$	253
		Location of Gain (Loss) on Derivative in Consolidated Statement of Income		Amount of Gain								Hedged Item in Fair Value Hedging Relationship		Location of  Gain (Loss) on Hedged Item  in Consolidated Statement  of Income		Amount of Gain
				(Loss) on Derivative												(Loss) on Hedged
				Recognized  in												Item Recognized in
				Consolidated												Consolidated
				Statement of Income												Statement of Income
				Three Months Ended September 30, 2012				Nine Months Ended September 30, 2012								Three Months Ended September 30, 2012				Nine Months Ended September 30, 2012
	(In millions)
	Derivatives designated as fair value hedges:
	Foreign exchange contracts	Processing fees and		$	26			$	30			Investment securities		Processing fees and		$	(26	)		$	(30	)
		other revenue												other revenue
	Interest-rate contracts	Processing fees and		(1		)		(7		)		Available-for-sale securities		Processing fees and		1				3
		other revenue												other revenue
	Interest-rate contracts	Processing fees and		22				62				Long-term debt		Processing fees and		(21		)		(58		)
		other revenue												other revenue
	Total			$	47			$	85							$	(46	)		$	(85	)
	Differences between the gains (losses) on the derivative and the gains (losses) on the hedged item, excluding any amounts recorded in net interest revenue, represent hedge ineffectiveness.
		Amount of Gain								Location of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income		Amount of Gain								Location of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income		Amount of Gain
		(Loss) on Derivative										(Loss) Reclassified										(Loss) on Derivative
		Recognized in Other										from OCI to										Recognized in
		Comprehensive										Consolidated										Consolidated
		Income										Statement of Income										Statement of Income
		Three Months Ended September 30, 2013				Nine Months Ended September 30, 2013						Three Months Ended September 30, 2013				Nine Months Ended September 30, 2013						Three Months Ended September 30, 2013		Nine Months Ended September 30, 2013
	(In millions)
	Derivatives designated as cash flow hedges:
	Interest-rate contracts	$	(1	)		$	10			Net interest revenue		$	(1	)		$	(3	)		Net interest revenue		$	1	$	3
	Foreign exchange contracts	(55		)		98				Net interest revenue		—				—				Net interest revenue		—		5
	Total	$	(56	)		$	108					$	(1	)		$	(3	)				$	1	$	8
		Amount of Gain								Location of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income		Amount of Gain								Location of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income		Amount of Gain
		(Loss) on Derivative										(Loss) Reclassified										(Loss) on Derivative
		Recognized in Other										from OCI to										Recognized in
		Comprehensive										Consolidated										Consolidated
		Income										Statement of Income										Statement of Income
		Three Months Ended September 30, 2012				Nine Months Ended September 30, 2012						Three Months Ended September 30, 2012				Nine Months Ended September 30, 2012						Three Months Ended September 30, 2012		Nine Months Ended September 30, 2012
	(In millions)
	Derivatives designated as cash flow hedges:
	Interest-rate contracts	$	—			$	3			Net interest revenue		$	(1	)		$	(4	)		Net interest revenue		$	1	$	2
	Foreign exchange contracts	(2		)		(1		)		Net interest revenue		—				—				Net interest revenue		2		2
	Total	$	(2	)		$	2					$	(1	)		$	(4	)				$	3	$	4

Offsetting_Arrangements_Tables

Offsetting Arrangements (Tables)	9 Months Ended
	Sep. 30, 2013
Offsetting [Abstract]	'
Offsetting Assets	'
	The following tables present information about the offsetting of derivative financial instruments and secured financing transactions, as of the dates indicated:
	Assets:	30-Sep-13								31-Dec-12
	(In millions)	Gross Amounts of Recognized Assets(1)		Gross Amounts Offset in Statement of Condition(2)			Net Amounts of Assets Presented in Statement of Condition			Gross Amounts of Recognized Assets(1)		Gross Amounts Offset in Statement of Condition(2)			Net Amounts of Assets Presented in Statement of Condition
	Derivatives:
	Interest-rate contracts	$	58	$	(45	)	$	13		$	223	$	(19	)	$	204
	Foreign exchange contracts	10,366		(3,757		)	6,609			9,378		(3,575		)	5,803
	Other derivative contracts	1		—			1			—		—			—
	Cash collateral netting	—		(2,303		)	(2,303		)	—		(1,451		)	(1,451		)
	Total derivatives	$	10,425	$	(6,105	)	$	4,320		$	9,601	$	(5,045	)	$	4,556
	Other financial instruments:
	Resale agreements and securities borrowing(3)	$	45,563	$	(29,974	)	$	15,589		$	35,658	$	(23,809	)	$	11,849
	Total derivatives and other financial instruments	$	55,988	$	(36,079	)	$	19,909		$	45,259	$	(28,854	)	$	16,405
	(1) Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.
	(2) Amounts subject to netting arrangements which have been determined to be legally enforceable.
	(3) Included in the $15,589 million as of September 30, 2013 was $5,827 million of resale agreements and $9,762 million of collateral related to securities borrowing. Included in the $11,849 million as of December 31, 2012 was $5,016 million of resale agreements and $6,833 million of collateral related to securities borrowing. Resale agreements and collateral related to securities borrowing were recorded in securities purchased under resale agreements and other assets, respectively, in our consolidated statement of condition. Refer to note 8 for additional information with respect to principal securities finance transactions.
		30-Sep-13										31-Dec-12
				Gross Amounts Not Offset in Statement of Condition(1)											Gross Amounts Not Offset in Statement of Condition(1)
	(In millions)	Net Amount of Assets Presented in Statement of Condition		Counterparty Netting			Collateral Received			Net Amount(2)		Net Amount of Assets Presented in Statement of Condition			Counterparty Netting			Collateral Received			Net Amount(2)
	Derivatives	$	4,320	$	—		$	(95	)	$	4,225	$	4,556		$	—		$	(105	)	$	4,451
	Resale agreements and securities borrowing	15,589		(144		)	(15,360		)	85		11,849			(126		)	(11,626		)	97
	Total	$	19,909	$	(144	)	$	(15,455	)	$	4,310	$	16,405		$	(126	)	$	(11,731	)	$	4,548
	(1) Amounts subject to netting arrangements which have been determined to be legally enforceable.
	(2) Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements.
Offsetting Liabilities	'
	The following tables present information about the offsetting of derivative financial instruments and secured financing transactions, as of the dates indicated:
	Liabilities:	30-Sep-13								31-Dec-12
	(In millions)	Gross Amounts of Recognized Liabilities(1)		Gross Amounts Offset in Statement of Condition(2)			Net Amounts of Liabilities Presented in Statement of Condition			Gross Amounts of Recognized Liabilities(1)		Gross Amounts Offset in Statement of Condition(2)			Net Amounts of Liabilities Presented in Statement of Condition
	Derivatives:
	Interest-rate contracts	$	307	$	(45	)	$	262		$	345	$	(19	)	$	326
	Foreign exchange contracts	10,261		(3,757		)	6,504			9,084		(3,574		)	5,510
	Other derivative contracts	9		—			9			9		—			9
	Cash collateral netting	—		(468		)	(468		)	—		(478		)	(478		)
	Total derivatives	$	10,577	$	(4,270	)	$	6,307		$	9,438	$	(4,071	)	$	5,367
	Other financial instruments:
	Repurchase agreements and securities lending(3)	$	46,488	$	(29,974	)	$	16,514		$	36,801	$	(23,809	)	$	12,992
	Total derivatives and other financial instruments	$	57,065	$	(34,244	)	$	22,821		$	46,239	$	(27,880	)	$	18,359
	(1) Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.
	(2) Amounts subject to netting arrangements which have been determined to be legally enforceable.
	(3) Included in the $16,514 million as of September 30, 2013 was $10,123 million of repurchase agreements and $6,391 million of collateral related to securities lending. Included in the $12,992 million as of December 31, 2012 was $8,006 million of repurchase agreements and $4,986 million of collateral related to securities lending. Repurchase agreements and collateral related to securities lending were recorded in securities sold under repurchase agreements and accrued expenses and other liabilities, respectively, in our consolidated statement of condition. Refer to note 8 for additional information with respect to principal securities finance transactions.
		30-Sep-13										31-Dec-12
				Gross Amounts Not Offset in Statement of Condition(1)											Gross Amounts Not Offset in Statement of Condition(1)
	(In millions)	Net Amount of Liabilities Presented in Statement of Condition		Counterparty Netting			Collateral Provided			Net Amount(2)		Net Amount of Liabilities Presented in Statement of Condition			Counterparty Netting			Collateral Provided			Net Amount(2)
	Derivatives	$	6,307	$	—		$	—		$	6,307	$	5,367		$	—		$	—		$	5,367
	Repurchase agreements and securities lending	$	16,514	$	(144	)	$	(14,002	)	2,368		12,992			(126		)	(12,067		)	799
	Total	$	22,821	$	(144	)	$	(14,002	)	$	8,675	$	18,359		$	(126	)	$	(12,067	)	$	6,166
	(1) Amounts subject to netting arrangements which have been determined to be legally enforceable.
	(2) Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements.

Net_Interest_Revenue_Tables

Net Interest Revenue (Tables)	9 Months Ended
	Sep. 30, 2013
Net Interest Revenue [Abstract]	'
Components of Interest Revenue and Interest Expense	'
	The following table presents the components of interest revenue and interest expense, and related net interest revenue, for the periods indicated:
		Three Months Ended September 30,				Nine Months Ended September 30,
	(In millions)	2013		2012		2013		2012
	Interest revenue:
	Deposits with banks	$	29	$	31	$	91	$	108
	Investment securities:
	U.S. Treasury and federal agencies	165		200		542		605
	State and political subdivisions	59		53		164		161
	Other investments	323		374		1,003		1,185
	Securities purchased under resale agreements	8		15		33		37
	Loans and leases	58		57		193		183
	Other interest-earning assets	1		—		4		2
	Total interest revenue	643		730		2,030		2,281
	Interest expense:
	Deposits	17		37		78		127
	Short-term borrowings	15		18		46		55
	Long-term debt	59		52		169		172
	Other interest-bearing liabilities	6		4		19		11
	Total interest expense	97		111		312		365
	Net interest revenue	$	546	$	619	$	1,718	$	1,916

Acquisition_and_Restructuring_1

Acquisition and Restructuring Costs (Tables)	9 Months Ended
	Sep. 30, 2013
Other Expenses [Abstract]	'
Schedule of Acquisition and Restructuring Costs	'
	The following table presents net acquisition and restructuring costs recorded in the periods indicated:
			Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)		2013			2012			2013			2012
	Acquisition costs		$	18		$	13		$	52		$	41
	Restructuring charges, net		12			15			22			45
	Total acquisition and restructuring costs		$	30		$	28		$	74		$	86
Costs Related to Acquisition and Restructuring	'
	The following table presents aggregate activity associated with accruals that resulted from the charges associated with the Business Operations and Information Technology Transformation program and the 2011 and 2012 expense control measures:
	(In millions)	Employee-			Real Estate Consolidation			Information Technology Costs			Asset and Other Write-Offs			Total
		Related
		Costs
	Balance as of December 31, 2012	$	195		$	49		$	5		$	13		$	262
	Additional accruals for Business Operations and Information Technology Transformation program	9			11			(1		)	—			19
	Additional accruals for 2012 expense control measures	(2		)	—			—			5			3
	Payments and adjustments	(125		)	(11		)	(4		)	(8		)	(148		)
	Balance as of September 30, 2013	$	77		$	49		$	—		$	10		$	136

Earnings_Per_Common_Share_Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Computation of Basic and Diluted Earnings Per Share	'
	The following table presents the computation of basic and diluted earnings per common share for the periods indicated:
		Three Months Ended September 30,						Nine Months Ended September 30,
	(Dollars in millions, except per share amounts)	2013			2012			2013			2012
	Net income	$	540		$	674		$	1,583		$	1,591
	Less:
	Preferred stock dividends	(7		)	(15		)	(20		)	(29		)
	Dividends and undistributed earnings allocated to participating securities(1)	(2		)	(5		)	(6		)	(11		)
	Net income available to common shareholders	$	531		$	654		$	1,557		$	1,551
	Average common shares outstanding (in thousands):
	Basic average common shares	442,860			472,355			449,742			479,536
	Effect of dilutive securities: common stock options and common stock awards	9,294			7,655			8,650			6,277
	Diluted average common shares	452,154			480,010			458,392			485,813
	Anti-dilutive securities(2)	1,788			5,443			2,384			5,613
	Earnings per Common Share:
	Basic	$	1.2		$	1.39		$	3.46		$	3.23
	Diluted	1.17			1.36			3.4			3.19
	(1) Represented the portion of net income available to common equity allocated to participating securities; participating securities, composed of unvested restricted stock and director stock awards, contain non-forfeitable rights to dividends during the vesting period on a basis equivalent to dividends paid to common shareholders.
	(2) Represented common stock options and other equity-based awards outstanding, but not included in the computation of diluted average shares because their effect was anti-dilutive.

Line_of_Business_Information_T

Line of Business Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Summary of Line of Business Results	'
		Three Months Ended September 30,
	(Dollars in millions,	Investment						Investment						Other						Total
	except where otherwise noted)	Servicing						Management
		2013			2012			2013			2012			2013			2012			2013			2012
	Fee revenue:
	Servicing fees	$	1,211		$	1,100		$	—		$	—		$	—		$	—		$	1,211		$	1,100
	Management fees	—			—			276			251			—			—			276			251
	Trading services	242			208			14			24			—			—			256			232
	Securities finance	69			81			5			10			—			—			74			91
	Processing fees and other	60			38			6			7			—			—			66			45
	Total fee revenue	1,582			1,427			301			292			—			—			1,883			1,719
	Net interest revenue	527			600			19			19									546			619
	Gains (losses) related to investment securities, net	(4		)	18			—			—			—			—			(4		)	18
	Total revenue	2,105			2,045			320			311			—			—			2,425			2,356
	Total expenses	1,496			1,459			191			205			35			(249		)	1,722			1,415
	Income before income tax expense	$	609		$	586		$	129		$	106		$	(35	)	$	249		$	703		$	941
	Pre-tax margin	29		%	29		%	40		%	34		%							29		%	40		%
	Average assets (in billions)	$	197.7		$	192.1		$	3.6		$	3.7								$	201.3		$	195.8
		Nine Months Ended September 30,
	(Dollars in millions,	Investment						Investment						Other						Total
	except where otherwise noted)	Servicing						Management
		2013			2012			2013			2012			2013			2012			2013			2012
	Fee revenue:
	Servicing fees	$	3,587		$	3,264		$	—		$	—		$	—		$	—		$	3,587		$	3,264
	Management fees	—			—			816			733			—			—			816			733
	Trading services	778			695			55			72			—			—			833			767
	Securities finance	255			296			28			35			—			—			283			331
	Processing fees and other	181			183			11			4			—			—			192			187
	Total fee revenue	4,801			4,438			910			844			—			—			5,711			5,282
	Net interest revenue	1,655			1,858			63			58			—			—			1,718			1,916
	Gains (losses) related to investment securities, net	(9		)	48			—			—			—			(46		)	(9		)	2
	Total revenue	6,447			6,344			973			902			—			(46		)	7,420			7,200
	Provision for loan losses	—			(1		)	—			—			—			—			—			(1		)
	Total expenses	4,628			4,537			624			654			94			(169		)	5,346			5,022
	Income before income tax expense	$	1,819		$	1,808		$	349		$	248		$	(94	)	$	123		$	2,074		$	2,179
	Pre-tax margin	28		%	28		%	36		%	27		%							28		%	30		%
	Average assets (in billions)	$	201.9		$	187.2		$	3.8		$	3.8								$	205.7		$	191

NonUS_Activities_Tables

Non-U.S. Activities (Tables)	9 Months Ended
	Sep. 30, 2013
Segments, Geographical Areas [Abstract]	'
Schedule of Results from Non-U.S. Operations	'
	The following table presents our non-U.S. financial results for the periods indicated. Results for 2012 reflect changes in methodology associated with funds transfer pricing and expense allocation reflected in results for 2013.
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Total fee revenue	$	771		$	700		$	2,347		$	2,169
	Net interest revenue	306			240			874			709
	Gains (losses) related to investment securities, net	(2		)	(4		)	(12		)	(36		)
	Total revenue	1,075			936			3,209			2,842
	Expenses	786			708			2,279			2,226
	Income before income taxes	289			228			930			616
	Income tax expense	74			57			228			153
	Net income	$	215		$	171		$	702		$	463
Summary of Non-U.S. Assets	'
	The following table presents the significant components of our non-U.S. assets as of the dates indicated, based on the domicile of the underlying counterparties:
	(In millions)	September 30, 2013			December 31, 2012
	Interest-bearing deposits with banks	$	5,221		$	20,665
	Investment securities	30,586			28,976
	Other assets	16,982			13,441
	Total non-U.S. assets	$	52,789		$	63,082

Basis_of_Presentation_Details

Basis of Presentation (Details)	9 Months Ended
	Sep. 30, 2013
	line_of_business
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Number of lines of business	2

Fair_Value_Narrative_Details

Fair Value (Narrative) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]	'	'
Fair value measurements with unobservable inputs, percent of total financial assets	7.00%	'
Fair value measurements with unobservable inputs, percent of total financial liabilities	1.00%	'
Percent of level 3 portfolio priced using non-binding broker quotes	98.00%	'
Percent of level 3 portfolio priced using internal model pricing	2.00%	'
Assets, level 1 to level 2 transfers	$0	$0
Assets, level 2 to level 1 transfers	0	0
Liabilities, level 1 to level 2 transfers	0	0
Liabilities, level 2 to level 1 transfers	$0	$0

Fair_Value_Schedule_of_Fair_Va

Fair Value (Schedule of Fair Value Measurements on a Recurring Basis) (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2013		Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	$916,000,000		$637,000,000
Reduction in assets from netting and the result of cash collateral deposited with derivative counterparties	2,300,000,000		1,450,000,000
Reduction in liabilities from netting and the result of cash collateral received from derivative counterparties	468,000,000		478,000,000
Pricing Methods with Significant Unobservable Market Inputs (Level 3)	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Assets, fair value disclosure	7,380,000,000		6,980,000,000
Liabilities, fair value disclosure	64,000,000		115,000,000
Recurring	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	916,000,000		637,000,000
Available-for-sale securities	99,982,000,000		109,682,000,000
Derivative assets	4,320,000,000		4,556,000,000
Other assets	101,000,000		68,000,000
Assets, fair value disclosure	105,319,000,000		114,943,000,000
Derivative instruments, liabilities	6,307,000,000		5,367,000,000
Other liabilities	101,000,000		66,000,000
Liabilities, fair value disclosure	6,408,000,000		5,433,000,000
Recurring | Foreign exchange contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	4,306,000,000		4,397,000,000
Derivative instruments, liabilities	6,050,000,000		5,032,000,000
Recurring | Interest-rate contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	13,000,000		159,000,000
Derivative instruments, liabilities	248,000,000		326,000,000
Recurring | Other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	1,000,000		'
Derivative instruments, liabilities	9,000,000		9,000,000
Recurring | U.S. government securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	20,000,000		20,000,000
Recurring | Non-U.S. government securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	392,000,000		391,000,000
Recurring | US Treasury and federal agencies, direct obligations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	738,000,000		841,000,000
Recurring | US Treasury and federal agencies, mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	24,575,000,000		32,212,000,000
Recurring | Total asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	29,664,000,000		32,483,000,000
Recurring | Asset-backed securities, student loans	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	14,871,000,000		16,421,000,000
Recurring | Asset-backed securities, credit cards	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	8,626,000,000		9,986,000,000
Recurring | Asset-backed securities, sub-prime	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	1,266,000,000		1,399,000,000
Recurring | Asset-backed securities, other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	4,901,000,000		4,677,000,000
Recurring | Total non-U.S. debt securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	24,609,000,000		25,128,000,000
Recurring | Non-U.S. debt securities, mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	11,001,000,000		11,405,000,000
Recurring | Non-U.S. debt securities, asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	5,467,000,000		6,218,000,000
Recurring | Non-US debt securities, government securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	3,541,000,000		3,199,000,000
Recurring | Non-U.S. debt securities, other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	4,600,000,000		4,306,000,000
Recurring | State and political subdivisions	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	9,298,000,000		7,551,000,000
Recurring | Collateralized mortgage obligations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	5,158,000,000		4,954,000,000
Recurring | Other U.S.debt securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	504,000,000		226,000,000
Available-for-sale securities	5,045,000,000		5,298,000,000
Recurring | U.S. equity securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	39,000,000		31,000,000
Recurring | Non-U.S. equity securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	2,000,000		1,000,000
Recurring | U.S. money-market mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	680,000,000		1,062,000,000
Recurring | Non-U.S. money-market mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	174,000,000		121,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1)	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	478,000,000		482,000,000
Available-for-sale securities	0		3,000,000
Derivative assets	0		0
Other assets	101,000,000		66,000,000
Assets, fair value disclosure	579,000,000		551,000,000
Derivative instruments, liabilities	'		'
Other liabilities	101,000,000		66,000,000
Liabilities, fair value disclosure	101,000,000		66,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1) | Foreign exchange contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Interest-rate contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	0		'
Recurring | Quoted Market Prices in Active Markets (Level 1) | U.S. government securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	20,000,000		20,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. government securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	392,000,000		391,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1) | US Treasury and federal agencies, direct obligations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		3,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1) | US Treasury and federal agencies, mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Total asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Asset-backed securities, student loans	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Asset-backed securities, credit cards	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Asset-backed securities, sub-prime	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Asset-backed securities, other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Total non-U.S. debt securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. debt securities, mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. debt securities, asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-US debt securities, government securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. debt securities, other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | State and political subdivisions	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Collateralized mortgage obligations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Other U.S.debt securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	66,000,000		71,000,000
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | U.S. equity securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. equity securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | U.S. money-market mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. money-market mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2)	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	438,000,000		155,000,000
Available-for-sale securities	92,679,000,000		102,812,000,000
Derivative assets	10,348,000,000		9,488,000,000
Other assets	0		2,000,000
Assets, fair value disclosure	103,465,000,000		112,457,000,000
Derivative instruments, liabilities	10,513,000,000		9,323,000,000
Other liabilities	0		0
Liabilities, fair value disclosure	10,513,000,000		9,323,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Foreign exchange contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	10,289,000,000		9,265,000,000
Derivative instruments, liabilities	10,206,000,000		8,978,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Interest-rate contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	58,000,000		223,000,000
Derivative instruments, liabilities	307,000,000		345,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	1,000,000		'
Derivative instruments, liabilities	0		0
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | US Treasury and federal agencies, direct obligations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	738,000,000		838,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | US Treasury and federal agencies, mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	23,834,000,000		31,387,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Total asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	24,922,000,000		27,834,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Asset-backed securities, student loans	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	14,503,000,000		15,833,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Asset-backed securities, credit cards	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	8,602,000,000		9,919,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Asset-backed securities, sub-prime	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	1,266,000,000		1,399,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Asset-backed securities, other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	551,000,000		683,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Total non-U.S. debt securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	23,029,000,000		23,909,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. debt securities, mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	10,661,000,000		10,850,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. debt securities, asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	4,668,000,000		5,694,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-US debt securities, government securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	3,541,000,000		3,199,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. debt securities, other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	4,159,000,000		4,166,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | State and political subdivisions	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	9,254,000,000		7,503,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Collateralized mortgage obligations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	4,971,000,000		4,837,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Other U.S.debt securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Trading account assets	438,000,000		155,000,000
Available-for-sale securities	5,036,000,000		5,289,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | U.S. equity securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	39,000,000		31,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. equity securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	2,000,000		1,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | U.S. money-market mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	680,000,000		1,062,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. money-market mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	174,000,000		121,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3)	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	7,303,000,000		6,867,000,000
Derivative assets	77,000,000		113,000,000
Other assets	0		0
Assets, fair value disclosure	7,380,000,000		6,980,000,000
Derivative instruments, liabilities	64,000,000		115,000,000
Other liabilities	0		0
Liabilities, fair value disclosure	64,000,000		115,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Foreign exchange contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	77,000,000		113,000,000
Derivative instruments, liabilities	55,000,000		106,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Interest-rate contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	0		0
Derivative instruments, liabilities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	0		'
Derivative instruments, liabilities	9,000,000		9,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | US Treasury and federal agencies, mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	741,000,000		825,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Total asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	4,742,000,000		4,649,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, student loans	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	368,000,000		588,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, credit cards	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	24,000,000		67,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, sub-prime	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	4,350,000,000		3,994,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Total non-U.S. debt securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	1,580,000,000		1,219,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. debt securities, mortgage-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	340,000,000		555,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. debt securities, asset-backed securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	799,000,000		524,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-US debt securities, government securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. debt securities, other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	441,000,000		140,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | State and political subdivisions	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	44,000,000		48,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Collateralized mortgage obligations	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	187,000,000		117,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Other U.S.debt securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	9,000,000		9,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | U.S. equity securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. equity securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | U.S. money-market mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. money-market mutual funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	0		0
Recurring | Impact of Netting	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	-6,105,000,000	[1]	-5,045,000,000
Other assets	0	[1]	0	[2]
Assets, fair value disclosure	-6,105,000,000	[1]	-5,045,000,000	[2]
Derivative instruments, liabilities	-4,270,000,000	[1]	-4,071,000,000
Other liabilities	0	[1]	0	[2]
Liabilities, fair value disclosure	-4,270,000,000	[1]	-4,071,000,000	[2]
Recurring | Impact of Netting | Foreign exchange contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	-6,060,000,000	[1]	-4,981,000,000	[2]
Derivative instruments, liabilities	-4,211,000,000	[1]	-4,052,000,000	[2]
Recurring | Impact of Netting | Interest-rate contracts	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	-45,000,000	[1]	-64,000,000	[2]
Derivative instruments, liabilities	-59,000,000	[1]	-19,000,000	[2]
Recurring | Impact of Netting | Other	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Derivative assets	0	[1]	'
Derivative instruments, liabilities	$0	[1]	$0	[2]
[1]	Represents counterparty netting against level-2 financial assets and liabilities, where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $2.30 billion and $468 million, respectively, for cash collateral received from and provided to derivative counterparties.
[2]	Represents counterparty netting against level-2 financial assets and liabilities, where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $1.45 billion and $478 million, respectively, for cash collateral received from and provided to derivative counterparties.

Fair_Value_Schedule_of_Fair_Va1

Fair Value (Schedule of Fair Value Measurements, Assets, Using Significant Unobservable Inputs) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	$6,894	$6,931	$6,980	$8,691
Transfers into Level 3, Assets	15	21	154	136
Transfers out of Level 3, Assets	-297	-993	-796	-5,210
Recorded in Revenue, Assets	-7	112	165	270
Recorded in Other Comprehensive Income, Assets	-15	25	25	37
Purchases, Assets	1,163	1,032	2,392	4,015
Issuances, Assets	0	0	0	0
Sales, Assets	-24	-45	-59	-118
Settlements, Assets	-349	-565	-1,481	-1,303
Fair Value, ending balance, Assets	7,380	6,518	7,380	6,518
Change in Unrealized Gains (Losses) Related to Financial Instruments, Assets, Held at Period End	-16	-47	29	-71
Derivative instruments, assets	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	'	'	'	178
Transfers into Level 3, Assets	'	'	'	0
Transfers out of Level 3, Assets	'	'	'	0
Recorded in Revenue, Assets	'	'	'	-137
Recorded in Other Comprehensive Income, Assets	'	'	'	0
Purchases, Assets	'	'	'	162
Sales, Assets	'	'	'	0
Settlements, Assets	'	'	'	-104
Fair Value, ending balance, Assets	'	99	'	99
Change in Unrealized Gains (Losses) Related to Financial Instruments, Assets, Held at Period End	'	'	'	-71
Foreign exchange contracts	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	121	160	113	168
Transfers into Level 3, Assets	0	0	0	0
Transfers out of Level 3, Assets	0	0	0	0
Recorded in Revenue, Assets	-21	-69	119	-127
Recorded in Other Comprehensive Income, Assets	0	0	0	0
Purchases, Assets	7	75	25	162
Sales, Assets	0	0	0	0
Settlements, Assets	-30	-67	-180	-104
Fair Value, ending balance, Assets	77	99	77	99
Change in Unrealized Gains (Losses) Related to Financial Instruments, Assets, Held at Period End	-16	-47	29	-71
Interest-rate contracts	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	'	'	'	10
Transfers into Level 3, Assets	'	'	'	0
Transfers out of Level 3, Assets	'	'	'	0
Recorded in Revenue, Assets	'	'	'	-10
Recorded in Other Comprehensive Income, Assets	'	'	'	0
Purchases, Assets	'	'	'	0
Sales, Assets	'	'	'	0
Settlements, Assets	'	'	'	0
Fair Value, ending balance, Assets	'	0	'	0
Change in Unrealized Gains (Losses) Related to Financial Instruments, Assets, Held at Period End	'	'	'	0
Categories of investments, marketable securities, available-for-sale securities	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	6,773	6,771	6,867	8,513
Transfers into Level 3, Assets	15	21	154	136
Transfers out of Level 3, Assets	-297	-993	-796	-5,210
Recorded in Revenue, Assets	14	181	46	407
Recorded in Other Comprehensive Income, Assets	-15	25	25	37
Purchases, Assets	1,156	957	2,367	3,853
Sales, Assets	-24	-45	-59	-118
Settlements, Assets	-319	-498	-1,301	-1,199
Fair Value, ending balance, Assets	7,303	6,419	7,303	6,419
Categories of investments, marketable securities, available-for-sale securities | US Treasury and federal agencies, mortgage-backed securities	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	864	933	825	1,189
Transfers into Level 3, Assets	'	'	'	50
Transfers out of Level 3, Assets	-93	'	-92	-251
Recorded in Revenue, Assets	'	'	'	'
Recorded in Other Comprehensive Income, Assets	-1	3	-1	3
Purchases, Assets	'	'	92	'
Issuances, Assets	'	'	'	'
Sales, Assets	'	'	'	'
Settlements, Assets	-29	-30	-83	-85
Fair Value, ending balance, Assets	741	906	741	906
Categories of investments, marketable securities, available-for-sale securities | Total asset-backed securities	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	4,252	3,852	4,649	3,749
Transfers into Level 3, Assets	'	12	'	33
Transfers out of Level 3, Assets	0	-47	-175	-388
Recorded in Revenue, Assets	13	12	41	37
Recorded in Other Comprehensive Income, Assets	-7	18	31	29
Purchases, Assets	793	608	1,358	1,401
Sales, Assets	-24	'	-59	-73
Settlements, Assets	-285	-279	-1,103	-612
Fair Value, ending balance, Assets	4,742	4,176	4,742	4,176
Categories of investments, marketable securities, available-for-sale securities | Asset-backed securities, student loans	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	380	484	588	860
Transfers into Level 3, Assets	'	'	'	0
Transfers out of Level 3, Assets	0	'	-175	-341
Recorded in Revenue, Assets	'	1	1	2
Recorded in Other Comprehensive Income, Assets	-2	5	6	-5
Purchases, Assets	'	'	0	'
Sales, Assets	'	'	-26	'
Settlements, Assets	-10	-12	-26	-38
Fair Value, ending balance, Assets	368	478	368	478
Categories of investments, marketable securities, available-for-sale securities | Asset-backed securities, credit cards	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	24	274	67	91
Transfers into Level 3, Assets	'	'	'	21
Transfers out of Level 3, Assets	0	-36	0	-36
Recorded in Revenue, Assets	'	1	0	4
Recorded in Other Comprehensive Income, Assets	0	-1	0	-5
Purchases, Assets	'	'	0	224
Sales, Assets	'	'	0	-61
Settlements, Assets	0	0	-43	0
Fair Value, ending balance, Assets	24	238	24	238
Categories of investments, marketable securities, available-for-sale securities | Asset-backed securities, other	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	3,848	3,094	3,994	2,798
Transfers into Level 3, Assets	'	12	'	12
Transfers out of Level 3, Assets	0	-11	0	-11
Recorded in Revenue, Assets	13	10	40	31
Recorded in Other Comprehensive Income, Assets	-5	14	25	39
Purchases, Assets	793	608	1,358	1,177
Sales, Assets	-24	'	-33	-12
Settlements, Assets	-275	-267	-1,034	-574
Fair Value, ending balance, Assets	4,350	3,460	4,350	3,460
Categories of investments, marketable securities, available-for-sale securities | Total non-U.S. debt securities	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	1,365	1,636	1,219	3,296
Transfers into Level 3, Assets	'	0	139	0
Transfers out of Level 3, Assets	-104	-823	-429	-4,257
Recorded in Revenue, Assets	1	1	4	1
Recorded in Other Comprehensive Income, Assets	-1	4	1	4
Purchases, Assets	313	349	727	2,169
Sales, Assets	0	'	0	0
Settlements, Assets	6	-11	-81	-57
Fair Value, ending balance, Assets	1,580	1,156	1,580	1,156
Categories of investments, marketable securities, available-for-sale securities | Non-U.S. debt securities, mortgage-backed securities	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	328	273	555	1,457
Transfers into Level 3, Assets	'	'	'	0
Transfers out of Level 3, Assets	0	-147	-208	-1,642
Recorded in Revenue, Assets	0	'	0	0
Recorded in Other Comprehensive Income, Assets	-1	0	-1	3
Purchases, Assets	0	156	0	463
Sales, Assets	0	'	0	0
Settlements, Assets	13	3	-6	4
Fair Value, ending balance, Assets	340	285	340	285
Categories of investments, marketable securities, available-for-sale securities | Non-U.S. debt securities, asset-backed securities	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	756	1,362	524	1,768
Transfers into Level 3, Assets	'	'	139	0
Transfers out of Level 3, Assets	-104	-676	-181	-2,243
Recorded in Revenue, Assets	1	1	4	1
Recorded in Other Comprehensive Income, Assets	1	4	2	4
Purchases, Assets	164	0	399	1,206
Sales, Assets	0	'	0	0
Settlements, Assets	-19	-14	-88	-59
Fair Value, ending balance, Assets	799	677	799	677
Categories of investments, marketable securities, available-for-sale securities | Non-U.S. debt securities, other	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	281	1	140	71
Transfers into Level 3, Assets	'	'	0	0
Transfers out of Level 3, Assets	0	0	-40	-372
Recorded in Revenue, Assets	0	'	0	0
Recorded in Other Comprehensive Income, Assets	-1	0	0	-3
Purchases, Assets	149	193	328	500
Sales, Assets	0	'	0	0
Settlements, Assets	12	0	13	-2
Fair Value, ending balance, Assets	441	194	441	194
Categories of investments, marketable securities, available-for-sale securities | State and political subdivisions	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	45	49	48	50
Transfers into Level 3, Assets	'	0	0	0
Transfers out of Level 3, Assets	0	0	0	0
Recorded in Revenue, Assets	0	0	0	0
Recorded in Other Comprehensive Income, Assets	-1	-1	-1	0
Purchases, Assets	0	0	0	0
Sales, Assets	'	'	0	'
Settlements, Assets	0	0	-3	-2
Fair Value, ending balance, Assets	44	48	44	48
Categories of investments, marketable securities, available-for-sale securities | Collateralized mortgage obligations	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	238	301	117	227
Transfers into Level 3, Assets	15	0	15	44
Transfers out of Level 3, Assets	-100	-123	-100	-314
Recorded in Revenue, Assets	0	168	1	369
Recorded in Other Comprehensive Income, Assets	-5	1	-5	1
Purchases, Assets	50	0	190	283
Sales, Assets	0	-45	0	-45
Settlements, Assets	-11	-178	-31	-441
Fair Value, ending balance, Assets	187	124	187	124
Categories of investments, marketable securities, available-for-sale securities | Other U.S.debt securities	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Assets	9	0	9	2
Transfers into Level 3, Assets	0	9	0	9
Transfers out of Level 3, Assets	0	0	0	0
Recorded in Revenue, Assets	0	0	0	0
Recorded in Other Comprehensive Income, Assets	0	0	0	0
Purchases, Assets	0	0	0	0
Sales, Assets	0	0	0	0
Settlements, Assets	0	0	0	-2
Fair Value, ending balance, Assets	$9	$9	$9	$9

Fair_Value_Schedule_of_Fair_Va2

Fair Value (Schedule of Fair Value Measurements, Liabilities, Using Significant Unobservable Inputs) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Liabilities	$117	$166	$115	$201
Transfers into Level 3, Liabilities	0	0	0	0
Transfers out of Level 3, Liabilities	0	0	0	0
Recorded in Revenue, Liabilities	-17	-58	59	-142
Recorded in Other Comprehensive Income, Liabilities	0	0	0	0
Purchases, Liabilities	0	0	0	0
Issuances, Liabilities	5	76	24	162
Sales, Liabilities	0	0	0	0
Settlements, Liabilities	-41	-75	-134	-112
Fair Value, ending balance, Liabilities	64	109	64	109
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of September 30, 2012	-15	-43	15	-70
Accrued expenses and other liabilities	'	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Liabilities	'	'	'	20
Recorded in Revenue, Liabilities	'	'	'	0
Purchases, Liabilities	'	'	'	'
Issuances, Liabilities	'	'	'	0
Sales, Liabilities	'	'	'	'
Settlements, Liabilities	'	'	'	-20
Fair Value, ending balance, Liabilities	'	0	'	0
Derivative instruments, liabilities | Accrued expenses and other liabilities	'	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Liabilities	117	166	115	181
Recorded in Revenue, Liabilities	-17	-58	59	-142
Issuances, Liabilities	5	76	24	162
Settlements, Liabilities	-41	-75	-134	-92
Fair Value, ending balance, Liabilities	64	109	64	109
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of September 30, 2012	-15	-43	15	-70
Foreign exchange contracts | Accrued expenses and other liabilities	'	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Liabilities	108	157	106	161
Recorded in Revenue, Liabilities	-17	-58	59	-131
Issuances, Liabilities	5	76	24	162
Sales, Liabilities	'	'	'	'
Settlements, Liabilities	-41	-75	-134	-92
Fair Value, ending balance, Liabilities	55	100	55	100
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of September 30, 2012	-15	-43	15	-70
Interest-rate contracts | Accrued expenses and other liabilities	'	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Liabilities	'	'	'	11
Recorded in Revenue, Liabilities	'	'	'	-11
Purchases, Liabilities	'	'	'	'
Issuances, Liabilities	'	'	'	0
Sales, Liabilities	'	'	'	'
Settlements, Liabilities	'	'	'	0
Fair Value, ending balance, Liabilities	'	0	'	0
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of September 30, 2012	'	'	'	0
Other | Accrued expenses and other liabilities	'	'	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Fair Value, beginning balance, Liabilities	9	9	9	9
Recorded in Revenue, Liabilities	0	0	0	0
Purchases, Liabilities	'	'	'	'
Issuances, Liabilities	0	0	0	0
Sales, Liabilities	'	'	'	'
Settlements, Liabilities	0	0	0	0
Fair Value, ending balance, Liabilities	9	9	9	9
Change in Unrealized (Gains) Losses Related to Financial Instruments Held as of September 30, 2012	$0	$0	$0	$0

Fair_Value_Level_3_Total_Reali

Fair Value (Level 3 Total Realized And Unrealized Gains And Losses Recorded In Revenue) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Total Revenue [Member]	'	'	'	'
Realized and Unrealized Gains and Losses [Line Items]	'	'	'	'
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	$10	$170	$106	$412
Change in Unrealized Gains (Losses) Related to Financial Instruments Held	-1	-4	14	-1
Trading services	'	'	'	'
Realized and Unrealized Gains and Losses [Line Items]	'	'	'	'
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	-4	-11	60	5
Change in Unrealized Gains (Losses) Related to Financial Instruments Held	-1	-4	14	-1
Total fee revenue	'	'	'	'
Realized and Unrealized Gains and Losses [Line Items]	'	'	'	'
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	-4	-11	60	5
Change in Unrealized Gains (Losses) Related to Financial Instruments Held	-1	-4	14	-1
Net interest revenue	'	'	'	'
Realized and Unrealized Gains and Losses [Line Items]	'	'	'	'
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	14	181	46	407
Change in Unrealized Gains (Losses) Related to Financial Instruments Held	$0	'	$0	$0

Fair_Value_Fair_Value_Inputs_A

Fair Value (Fair Value Inputs, Assets and Liabilities, Quantitative Information) (Details) (Pricing Methods with Significant Unobservable Market Inputs (Level 3), USD $)	9 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Assets, fair value disclosure	7,380		6,980
Liabilities, fair value disclosure	64		115
Derivative instruments, liabilities	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Derivative instruments, foreign exchange contracts, liabilities	55		106
Derivative instruments, other, liabilities	9		9
Derivative instruments, assets	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Derivative instruments, foreign exchange contracts, assets	77		113
Asset-backed securities, student loans	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	368		588
Asset-backed securities, credit cards	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	24		67
Asset-backed securities, other	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	4,350		3,994
State and political subdivisions	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	44		48
Discounted cash flows | Derivative instruments, liabilities | Weighted average	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Participant redemptions	7.10%		6.70%
Discounted cash flows | Asset-backed securities, student loans | Weighted average	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Credit spread	4.40%		6.70%
Discounted cash flows | Asset-backed securities, credit cards | Weighted average	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Credit spread	2.10%		7.10%
Discounted cash flows | Asset-backed securities, other | Weighted average	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Credit spread	1.00%		1.50%
Discounted cash flows | State and political subdivisions | Weighted average	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Credit spread	2.00%		1.90%
Option model | Derivative instruments, liabilities | Weighted average	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Volatility	13.10%		9.80%
Option model | Derivative instruments, assets | Weighted average	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Volatility	13.30%		9.80%
Significant Unobservable Inputs Readily Available [Member]	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Assets, fair value disclosure	259	[1]	343	[1]
Liabilities, fair value disclosure	64	[1]	115	[1]
Significant Unobservable Inputs Readily Available [Member] | Derivative instruments, liabilities	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Derivative instruments, foreign exchange contracts, liabilities	55	[1]	106	[1]
Derivative instruments, other, liabilities	9	[1]	9	[1]
Significant Unobservable Inputs Readily Available [Member] | Derivative instruments, assets	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Derivative instruments, foreign exchange contracts, assets	77	[1]	113	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed securities, student loans	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	13	[1]	12	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed securities, credit cards	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	24	[1]	67	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed securities, other	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	101	[1]	103	[1]
Significant Unobservable Inputs Readily Available [Member] | State and political subdivisions	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	44	[1]	48	[1]
Significant Unobservable Inputs Readily Available [Member] | Discounted cash flows | Derivative instruments, liabilities	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Derivative instruments, other, liabilities	9		9
Significant Unobservable Inputs Readily Available [Member] | Discounted cash flows | Asset-backed securities, student loans	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	13		12
Significant Unobservable Inputs Readily Available [Member] | Discounted cash flows | Asset-backed securities, credit cards	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	24		67
Significant Unobservable Inputs Readily Available [Member] | Discounted cash flows | Asset-backed securities, other	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	101		103
Significant Unobservable Inputs Readily Available [Member] | Discounted cash flows | State and political subdivisions	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Available-for-sale securities	44		48
Significant Unobservable Inputs Readily Available [Member] | Option model | Derivative instruments, liabilities	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Derivative instruments, foreign exchange contracts, liabilities	55		106
Significant Unobservable Inputs Readily Available [Member] | Option model | Derivative instruments, assets	'		'
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]	'		'
Derivative instruments, foreign exchange contracts, assets	77		113
[1]	Information with respect to these model-priced financial assets and liabilities is provided in the preceding table.

Fair_Value_Schedule_of_Availab

Fair Value (Schedule of Availability of Significant Unobservable Inputs by Balance Sheet Classification) (Details) (Pricing Methods with Significant Unobservable Market Inputs (Level 3), USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Assets:	'		'
Assets, fair value disclosure	$7,380		$6,980
Liabilities:	'		'
Liabilities, fair value disclosure	64		115
Derivative instruments, liabilities	'		'
Liabilities:	'		'
Derivative instruments, foreign exchange contracts, liabilities	55		106
Derivative instruments, other, liabilities	9		9
Derivative instruments, assets	'		'
Assets:	'		'
Derivative instruments, foreign exchange contracts, assets	77		113
U.S. Treasury and federal agencies, mortgage-backed securities	'		'
Assets:	'		'
Available-for-sale securities	741		825
Asset-backed securities, student loans	'		'
Assets:	'		'
Available-for-sale securities	368		588
Asset-backed securities, credit cards	'		'
Assets:	'		'
Available-for-sale securities	24		67
Asset-backed securities, other	'		'
Assets:	'		'
Available-for-sale securities	4,350		3,994
Non-U.S. debt securities, mortgage-backed securities	'		'
Assets:	'		'
Available-for-sale securities	340		555
Non-U.S. debt securities, asset-backed securities	'		'
Assets:	'		'
Available-for-sale securities	799		524
Non-U.S. debt securities, other	'		'
Assets:	'		'
Available-for-sale securities	441		140
State and political subdivisions	'		'
Assets:	'		'
Available-for-sale securities	44		48
Collateralized mortgage obligations	'		'
Assets:	'		'
Available-for-sale securities	187		117
Other U.S.debt securities	'		'
Assets:	'		'
Available-for-sale securities	9		9
Significant Unobservable Inputs Readily Available [Member]	'		'
Assets:	'		'
Assets, fair value disclosure	259	[1]	343	[1]
Liabilities:	'		'
Liabilities, fair value disclosure	64	[1]	115	[1]
Significant Unobservable Inputs Readily Available [Member] | Derivative instruments, liabilities	'		'
Liabilities:	'		'
Derivative instruments, foreign exchange contracts, liabilities	55	[1]	106	[1]
Derivative instruments, other, liabilities	9	[1]	9	[1]
Significant Unobservable Inputs Readily Available [Member] | Derivative instruments, assets	'		'
Assets:	'		'
Derivative instruments, foreign exchange contracts, assets	77	[1]	113	[1]
Significant Unobservable Inputs Readily Available [Member] | U.S. Treasury and federal agencies, mortgage-backed securities	'		'
Assets:	'		'
Available-for-sale securities	0	[1]	0	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed securities, student loans	'		'
Assets:	'		'
Available-for-sale securities	13	[1]	12	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed securities, credit cards	'		'
Assets:	'		'
Available-for-sale securities	24	[1]	67	[1]
Significant Unobservable Inputs Readily Available [Member] | Asset-backed securities, other	'		'
Assets:	'		'
Available-for-sale securities	101	[1]	103	[1]
Significant Unobservable Inputs Readily Available [Member] | Non-U.S. debt securities, mortgage-backed securities	'		'
Assets:	'		'
Available-for-sale securities	0	[1]	0	[1]
Significant Unobservable Inputs Readily Available [Member] | Non-U.S. debt securities, asset-backed securities	'		'
Assets:	'		'
Available-for-sale securities	0	[1]	0	[1]
Significant Unobservable Inputs Readily Available [Member] | Non-U.S. debt securities, other	'		'
Assets:	'		'
Available-for-sale securities	0	[1]	0	[1]
Significant Unobservable Inputs Readily Available [Member] | State and political subdivisions	'		'
Assets:	'		'
Available-for-sale securities	44	[1]	48	[1]
Significant Unobservable Inputs Readily Available [Member] | Collateralized mortgage obligations	'		'
Assets:	'		'
Available-for-sale securities	0	[1]	0	[1]
Significant Unobservable Inputs Readily Available [Member] | Other U.S.debt securities	'		'
Assets:	'		'
Available-for-sale securities	0	[1]	0	[1]
Significant Unobservable Inputs Not Readily Available [Member]	'		'
Assets:	'		'
Assets, fair value disclosure	7,121	[2]	6,637	[2]
Liabilities:	'		'
Liabilities, fair value disclosure	0	[2]	0	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Derivative instruments, liabilities	'		'
Liabilities:	'		'
Derivative instruments, foreign exchange contracts, liabilities	0	[2]	0	[2]
Derivative instruments, other, liabilities	0	[2]	0	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Derivative instruments, assets	'		'
Assets:	'		'
Derivative instruments, foreign exchange contracts, assets	0	[2]	0	[2]
Significant Unobservable Inputs Not Readily Available [Member] | U.S. Treasury and federal agencies, mortgage-backed securities	'		'
Assets:	'		'
Available-for-sale securities	741	[2]	825	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Asset-backed securities, student loans	'		'
Assets:	'		'
Available-for-sale securities	355	[2]	576	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Asset-backed securities, credit cards	'		'
Assets:	'		'
Available-for-sale securities	0	[2]	0	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Asset-backed securities, other	'		'
Assets:	'		'
Available-for-sale securities	4,249	[2]	3,891	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Non-U.S. debt securities, mortgage-backed securities	'		'
Assets:	'		'
Available-for-sale securities	340	[2]	555	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Non-U.S. debt securities, asset-backed securities	'		'
Assets:	'		'
Available-for-sale securities	799	[2]	524	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Non-U.S. debt securities, other	'		'
Assets:	'		'
Available-for-sale securities	441	[2]	140	[2]
Significant Unobservable Inputs Not Readily Available [Member] | State and political subdivisions	'		'
Assets:	'		'
Available-for-sale securities	0	[2]	0	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Collateralized mortgage obligations	'		'
Assets:	'		'
Available-for-sale securities	187	[2]	117	[2]
Significant Unobservable Inputs Not Readily Available [Member] | Other U.S.debt securities	'		'
Assets:	'		'
Available-for-sale securities	$9	[2]	$9	[2]
[1]	Information with respect to these model-priced financial assets and liabilities is provided in the preceding table.
[2]	Fair value for these financial assets is measured using non-binding broker or dealer quotes.

Fair_Value_Carrying_Value_and_

Fair Value (Carrying Value and Estimated Fair Value of Financial Instruments) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Financial Assets:	'	'	'	'
Cash and due from banks	$3,896	$2,590	$6,432	$2,193
Interest-bearing deposits with banks	38,636	50,763	'	'
Securities purchased under resale agreements	5,827	5,016	'	'
Investment securities held to maturity	16,698	11,379	'	'
Financial Liabilities:	'	'	'	'
Noninterest-bearing	45,679	44,445	'	'
Interest-bearing—U.S.	6,575	19,201	'	'
Interest-bearing—non-U.S.	101,945	100,535	'	'
Securities sold under repurchase agreements	10,123	8,006	'	'
Federal funds purchased	94	399	'	'
Other short-term borrowings	3,657	4,502	'	'
Long-term debt	8,748	7,429	'	'
Reported Amount	'	'	'	'
Financial Assets:	'	'	'	'
Cash and due from banks	3,896	2,590	'	'
Interest-bearing deposits with banks	38,636	50,763	'	'
Securities purchased under resale agreements	5,827	5,016	'	'
Investment securities held to maturity	16,698	11,379	'	'
Loans (excluding leases)	14,445	11,121	'	'
Financial Liabilities:	'	'	'	'
Noninterest-bearing	45,679	44,445	'	'
Interest-bearing—U.S.	6,575	19,201	'	'
Interest-bearing—non-U.S.	101,945	100,535	'	'
Securities sold under repurchase agreements	10,123	8,006	'	'
Federal funds purchased	94	399	'	'
Other short-term borrowings	3,657	4,502	'	'
Long-term debt	8,748	7,429	'	'
Estimated Fair Value	'	'	'	'
Financial Assets:	'	'	'	'
Cash and due from banks	3,896	2,590	'	'
Interest-bearing deposits with banks	38,636	50,763	'	'
Securities purchased under resale agreements	5,827	5,016	'	'
Investment securities held to maturity	16,543	11,661	'	'
Loans (excluding leases)	14,431	11,166	'	'
Financial Liabilities:	'	'	'	'
Noninterest-bearing	45,679	44,445	'	'
Interest-bearing—U.S.	6,575	19,201	'	'
Interest-bearing—non-U.S.	101,945	100,535	'	'
Securities sold under repurchase agreements	10,123	8,006	'	'
Federal funds purchased	94	399	'	'
Other short-term borrowings	3,657	4,502	'	'
Long-term debt	9,101	7,780	'	'
Quoted Market Prices in Active Markets (Level 1) | Estimated Fair Value	'	'	'	'
Financial Assets:	'	'	'	'
Cash and due from banks	3,896	2,590	'	'
Interest-bearing deposits with banks	0	0	'	'
Securities purchased under resale agreements	0	0	'	'
Investment securities held to maturity	0	0	'	'
Loans (excluding leases)	0	0	'	'
Financial Liabilities:	'	'	'	'
Noninterest-bearing	0	0	'	'
Interest-bearing—U.S.	0	0	'	'
Interest-bearing—non-U.S.	0	0	'	'
Securities sold under repurchase agreements	0	0	'	'
Federal funds purchased	0	0	'	'
Other short-term borrowings	0	0	'	'
Long-term debt	0	0	'	'
Pricing Methods with Significant Observable Market Inputs (Level 2) | Estimated Fair Value	'	'	'	'
Financial Assets:	'	'	'	'
Cash and due from banks	0	0	'	'
Interest-bearing deposits with banks	38,636	50,763	'	'
Securities purchased under resale agreements	5,827	5,016	'	'
Investment securities held to maturity	16,543	11,661	'	'
Loans (excluding leases)	13,968	10,276	'	'
Financial Liabilities:	'	'	'	'
Noninterest-bearing	45,679	44,445	'	'
Interest-bearing—U.S.	6,575	19,201	'	'
Interest-bearing—non-U.S.	101,945	100,535	'	'
Securities sold under repurchase agreements	10,123	8,006	'	'
Federal funds purchased	94	399	'	'
Other short-term borrowings	3,657	4,502	'	'
Long-term debt	8,125	6,871	'	'
Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Estimated Fair Value	'	'	'	'
Financial Assets:	'	'	'	'
Cash and due from banks	0	0	'	'
Interest-bearing deposits with banks	0	0	'	'
Securities purchased under resale agreements	0	0	'	'
Investment securities held to maturity	0	0	'	'
Loans (excluding leases)	463	890	'	'
Financial Liabilities:	'	'	'	'
Noninterest-bearing	0	0	'	'
Interest-bearing—U.S.	0	0	'	'
Interest-bearing—non-U.S.	0	0	'	'
Securities sold under repurchase agreements	0	0	'	'
Federal funds purchased	0	0	'	'
Other short-term borrowings	0	0	'	'
Long-term debt	$976	$909	'	'

Investment_Securities_Narrativ

Investment Securities (Narrative) (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
	country			security
				country
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Other-than-temporary impairment recorded	$10,000,000		$6,000,000	$20,000,000		$27,000,000	'
Impairment associated with adverse changes in timing of expected future cash flows	2,000,000		5,000,000	6,000,000		13,000,000	'
Impairment associated with management's intent to sell impaired securities prior to recovery in value	0		0	6,000,000		0	'
Impairment associated with expected credit losses	-8,000,000		-1,000,000	-8,000,000		-14,000,000	'
Available for sale, gross unrealized gains	1,292,000,000		'	1,292,000,000		'	2,001,000,000
Available for sale, gross unrealized losses	-1,057,000,000		'	-1,057,000,000		'	-882,000,000
Number of peripheral european countries	4		'	4		'	'
Gross pre-tax unrealized losses on securities	'		'	-1,560,000,000		'	'
Number of available for sale and held to maturity securities in gross pre-tax unrealized loss position	'		'	2,607		'	'
Pledged Financial Instruments, Not Separately Reported, Securities	48,280,000,000		'	48,280,000,000		'	46,660,000,000
U.S. agency residential mortgage-backed securities	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Other-than-temporary impairment recorded	0		0	0		0	'
Non-U.S. debt securities, mortgage-backed securities	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Other-than-temporary impairment recorded	2,000,000		5,000,000	6,000,000		19,000,000	'
Impairment associated with adverse changes in timing of expected future cash flows	'		'	'		13,000,000	'
Available for sale, gross unrealized gains	241,000,000		'	241,000,000		'	313,000,000
Available for sale, gross unrealized losses	-13,000,000		'	-13,000,000		'	-27,000,000
Non-U.S. debt securities, mortgage-backed securities | European Periphery	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Other-than-temporary impairment recorded	0		0	6,000,000		6,000,000	'
Total exposure to asset backed securities	570,000,000		'	570,000,000		'	'
Aggregate pre-tax gross unrealized gain (loss) on available for sale securities	39,000,000		'	39,000,000		'	'
Available for sale, gross unrealized gains	63,000,000		'	63,000,000		'	'
Available for sale, gross unrealized losses	-24,000,000		'	-24,000,000		'	'
Non-U.S. debt securities, mortgage-backed securities | Spain	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Total exposure to asset backed securities	269,000,000		'	269,000,000		'	'
Non-U.S. debt securities, mortgage-backed securities | Italy	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Total exposure to asset backed securities	106,000,000		'	106,000,000		'	'
Non-U.S. debt securities, mortgage-backed securities | Ireland	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Total exposure to asset backed securities	118,000,000		'	118,000,000		'	'
Non-U.S. debt securities, mortgage-backed securities | Portugal	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Total exposure to asset backed securities	77,000,000		'	77,000,000		'	'
Asset-backed securities, student loans	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Other-than-temporary impairment recorded	0		0	0		0	'
Available for sale, gross unrealized gains	94,000,000	[1]	'	94,000,000	[1]	'	100,000,000	[1]
Available for sale, gross unrealized losses	-302,000,000	[1]	'	-302,000,000	[1]	'	-508,000,000	[1]
Federal Family Education Loan Program	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Federal government credit support guarantee, percentage minimum	'		'	97.00%		'	'
Collective credit support, percentage minimum	'		'	100.00%		'	'
Average remaining term of FFELP loan-backed securities	'		'	'5 years		'	'
Maximum concentration risk on credit instruments (less than)	'		'	900,000,000		'	'
Direct sovereign debt	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Total exposure to asset backed securities	0		'	0		'	'
State and political subdivisions	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Other-than-temporary impairment recorded	'		0	0		0	'
Available for sale, gross unrealized gains	171,000,000		'	171,000,000		'	234,000,000
Available for sale, gross unrealized losses	-180,000,000		'	-180,000,000		'	-67,000,000
U.S. non-agency residential mortgage-backed securities	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Other-than-temporary impairment recorded	0		1,000,000	0		8,000,000	'
Collateralized mortgage obligations	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Other-than-temporary impairment recorded	8,000,000		'	8,000,000		'	'
Available for sale, gross unrealized gains	79,000,000		'	79,000,000		'	151,000,000
Available for sale, gross unrealized losses	($73,000,000)		'	($73,000,000)		'	($15,000,000)
Minimum	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Percentage change in additional house price declines	'		'	10.00%		'	'
Maximum	'		'	'		'	'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'	'		'	'
Percentage change in additional house price declines	'		'	18.00%		'	'
[1]	Substantially composed of securities guaranteed by the federal government with respect to at least 97% of defaulted principal and accrued interest on the underlying loans.

Investment_Securities_Schedule

Investment Securities (Schedule of Marketable Securities) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	$99,747		$108,563
Available for sale, gross unrealized gains	1,292		2,001
Available for sale, gross unrealized losses	1,057		882
Available for sale, fair value	99,982		109,682
Held to maturity, amortized cost	16,698		11,379
Held to maturity, gross unrealized gains	349		373
Held to maturity, gross unrealized losses	504		91
Held to maturity, fair value	16,543		11,661
Total asset-backed securities	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	29,871		32,897
Available for sale, gross unrealized gains	270		320
Available for sale, gross unrealized losses	477		734
Available for sale, fair value	29,664		32,483
Held to maturity, amortized cost	2,851		16
Held to maturity, gross unrealized gains	0		0
Held to maturity, gross unrealized losses	14		0
Held to maturity, fair value	2,837		16
US Treasury and federal agencies, direct obligations	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	729		823
Available for sale, gross unrealized gains	11		19
Available for sale, gross unrealized losses	2		1
Available for sale, fair value	738		841
Held to maturity, amortized cost	5,003		5,000
Held to maturity, gross unrealized gains	0		0
Held to maturity, gross unrealized losses	390		8
Held to maturity, fair value	4,613		4,992
US Treasury and federal agencies, mortgage-backed securities	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	24,562		31,640
Available for sale, gross unrealized gains	275		598
Available for sale, gross unrealized losses	262		26
Available for sale, fair value	24,575		32,212
Held to maturity, amortized cost	100		153
Held to maturity, gross unrealized gains	7		11
Held to maturity, gross unrealized losses	0		0
Held to maturity, fair value	107		164
Asset-backed securities, student loans	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	15,079	[1]	16,829	[1]
Available for sale, gross unrealized gains	94	[1]	100	[1]
Available for sale, gross unrealized losses	302	[1]	508	[1]
Available for sale, fair value	14,871	[1]	16,421	[1]
Held to maturity, amortized cost	1,502	[1]	0	[1]
Held to maturity, gross unrealized gains	0	[1]	0	[1]
Held to maturity, gross unrealized losses	11	[1]	0	[1]
Held to maturity, fair value	1,491	[1]	0	[1]
Asset-backed securities, credit cards	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	8,649		9,928
Available for sale, gross unrealized gains	23		61
Available for sale, gross unrealized losses	46		3
Available for sale, fair value	8,626		9,986
Held to maturity, amortized cost	531		0
Held to maturity, gross unrealized gains	0		0
Held to maturity, gross unrealized losses	0		0
Held to maturity, fair value	531		0
Asset-backed securities, sub-prime	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	1,371		1,557
Available for sale, gross unrealized gains	5		4
Available for sale, gross unrealized losses	110		162
Available for sale, fair value	1,266		1,399
Asset-backed securities, other	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	4,772		4,583
Available for sale, gross unrealized gains	148		155
Available for sale, gross unrealized losses	19		61
Available for sale, fair value	4,901		4,677
Held to maturity, amortized cost	818		16
Held to maturity, gross unrealized gains	0		0
Held to maturity, gross unrealized losses	3		0
Held to maturity, fair value	815		16
Total non-U.S. debt securities	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	24,311		24,717
Available for sale, gross unrealized gains	328		443
Available for sale, gross unrealized losses	30		32
Available for sale, fair value	24,609		25,128
Held to maturity, amortized cost	5,801		3,726
Held to maturity, gross unrealized gains	148		101
Held to maturity, gross unrealized losses	69		71
Held to maturity, fair value	5,880		3,756
Non-U.S. debt securities, mortgage-backed securities	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	10,773		11,119
Available for sale, gross unrealized gains	241		313
Available for sale, gross unrealized losses	13		27
Available for sale, fair value	11,001		11,405
Held to maturity, amortized cost	4,109		3,122
Held to maturity, gross unrealized gains	130		85
Held to maturity, gross unrealized losses	67		68
Held to maturity, fair value	4,172		3,139
Non-U.S. debt securities, asset-backed securities	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	5,445		6,180
Available for sale, gross unrealized gains	25		42
Available for sale, gross unrealized losses	3		4
Available for sale, fair value	5,467		6,218
Held to maturity, amortized cost	1,486		434
Held to maturity, gross unrealized gains	18		16
Held to maturity, gross unrealized losses	2		1
Held to maturity, fair value	1,502		449
Non-US debt securities, government securities	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	3,537		3,197
Available for sale, gross unrealized gains	4		2
Available for sale, gross unrealized losses	0		0
Available for sale, fair value	3,541		3,199
Held to maturity, amortized cost	16		3
Held to maturity, gross unrealized gains	0		0
Held to maturity, gross unrealized losses	0		0
Held to maturity, fair value	16		3
Non-U.S. debt securities, other	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	4,556		4,221
Available for sale, gross unrealized gains	58		86
Available for sale, gross unrealized losses	14		1
Available for sale, fair value	4,600		4,306
Held to maturity, amortized cost	190		167
Held to maturity, gross unrealized gains	0		0
Held to maturity, gross unrealized losses	0		2
Held to maturity, fair value	190		165
State and political subdivisions	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	9,307		7,384
Available for sale, gross unrealized gains	171		234
Available for sale, gross unrealized losses	180		67
Available for sale, fair value	9,298		7,551
Held to maturity, amortized cost	61		74
Held to maturity, gross unrealized gains	1		2
Held to maturity, gross unrealized losses	0		0
Held to maturity, fair value	62		76
Collateralized mortgage obligations	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	5,152		4,818
Available for sale, gross unrealized gains	79		151
Available for sale, gross unrealized losses	73		15
Available for sale, fair value	5,158		4,954
Held to maturity, amortized cost	2,882		2,410
Held to maturity, gross unrealized gains	193		259
Held to maturity, gross unrealized losses	31		12
Held to maturity, fair value	3,044		2,657
Other U.S.debt securities	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	4,925		5,072
Available for sale, gross unrealized gains	153		233
Available for sale, gross unrealized losses	33		7
Available for sale, fair value	5,045		5,298
U.S. equity securities	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	34		28
Available for sale, gross unrealized gains	5		3
Available for sale, gross unrealized losses	0		0
Available for sale, fair value	39		31
Non-U.S. equity securities	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	2		1
Available for sale, gross unrealized gains	0		0
Available for sale, gross unrealized losses	0		0
Available for sale, fair value	2		1
U.S. money-market mutual funds	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	680		1,062
Available for sale, gross unrealized gains	0		0
Available for sale, gross unrealized losses	0		0
Available for sale, fair value	680		1,062
Non-U.S. money-market mutual funds	'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'
Available for sale, amortized cost	174		121
Available for sale, gross unrealized gains	0		0
Available for sale, gross unrealized losses	0		0
Available for sale, fair value	$174		$121
[1]	Substantially composed of securities guaranteed by the federal government with respect to at least 97% of defaulted principal and accrued interest on the underlying loans.

Investment_Securities_Schedule1

Investment Securities (Schedule of Gross Pre-Tax Unrealized Losses on Investment Securities) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	$25,178	$9,124
Available for sale, Gross Unrealized Losses Less than 12 months	532	56
Available for sale, Fair Value 12 months or longer	12,855	15,885
Available for sale, Gross Unrealized Losses 12 months or longer	525	826
Available for sale, Fair Value Total	38,033	25,009
Available for sale, Gross Unrealized Losses Total	1,057	882
Held to maturity, Fair Value Less than 12 months	9,202	3,968
Held to maturity, Gross Unrealized Losses Less than 12 months	438	10
Held to maturity, Fair Value 12 months or longer	989	1,338
Held to maturity, Gross Unrealized Losses 12 months or longer	66	81
Held to maturity, Fair Value Total	10,191	5,306
Held to maturity, Gross Unrealized Losses Total	504	91
Asset-backed securities	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	6,769	2,152
Available for sale, Gross Unrealized Losses Less than 12 months	71	22
Available for sale, Fair Value 12 months or longer	9,125	12,576
Available for sale, Gross Unrealized Losses 12 months or longer	406	712
Available for sale, Fair Value Total	15,894	14,728
Available for sale, Gross Unrealized Losses Total	477	734
Held to maturity, Fair Value Less than 12 months	1,814	'
Held to maturity, Gross Unrealized Losses Less than 12 months	14	'
Held to maturity, Fair Value 12 months or longer	0	'
Held to maturity, Gross Unrealized Losses 12 months or longer	0	'
Held to maturity, Fair Value Total	1,814	'
Held to maturity, Gross Unrealized Losses Total	14	'
US Treasury and federal agencies, direct obligations	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	158	0
Available for sale, Gross Unrealized Losses Less than 12 months	1	0
Available for sale, Fair Value 12 months or longer	117	132
Available for sale, Gross Unrealized Losses 12 months or longer	1	1
Available for sale, Fair Value Total	275	132
Available for sale, Gross Unrealized Losses Total	2	1
Held to maturity, Fair Value Less than 12 months	4,611	3,792
Held to maturity, Gross Unrealized Losses Less than 12 months	390	8
Held to maturity, Fair Value 12 months or longer	0	0
Held to maturity, Gross Unrealized Losses 12 months or longer	0	0
Held to maturity, Fair Value Total	4,611	3,792
Held to maturity, Gross Unrealized Losses Total	390	8
US Treasury and federal agencies, mortgage-backed securities	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	9,721	3,486
Available for sale, Gross Unrealized Losses Less than 12 months	232	18
Available for sale, Fair Value 12 months or longer	1,933	865
Available for sale, Gross Unrealized Losses 12 months or longer	30	8
Available for sale, Fair Value Total	11,654	4,351
Available for sale, Gross Unrealized Losses Total	262	26
Asset-backed securities, student loans	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	2,123	625
Available for sale, Gross Unrealized Losses Less than 12 months	19	6
Available for sale, Fair Value 12 months or longer	7,463	10,241
Available for sale, Gross Unrealized Losses 12 months or longer	283	502
Available for sale, Fair Value Total	9,586	10,866
Available for sale, Gross Unrealized Losses Total	302	508
Held to maturity, Fair Value Less than 12 months	1,234	'
Held to maturity, Gross Unrealized Losses Less than 12 months	11	'
Held to maturity, Fair Value 12 months or longer	0	'
Held to maturity, Gross Unrealized Losses 12 months or longer	0	'
Held to maturity, Fair Value Total	1,234	'
Held to maturity, Gross Unrealized Losses Total	11	'
Asset-backed securities, credit cards	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	3,734	888
Available for sale, Gross Unrealized Losses Less than 12 months	46	3
Available for sale, Fair Value 12 months or longer	0	0
Available for sale, Gross Unrealized Losses 12 months or longer	0	0
Available for sale, Fair Value Total	3,734	888
Available for sale, Gross Unrealized Losses Total	46	3
Asset-backed securities, sub-prime	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	16	0
Available for sale, Gross Unrealized Losses Less than 12 months	1	0
Available for sale, Fair Value 12 months or longer	1,193	1,346
Available for sale, Gross Unrealized Losses 12 months or longer	109	162
Available for sale, Fair Value Total	1,209	1,346
Available for sale, Gross Unrealized Losses Total	110	162
Asset-backed securities, other	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	896	639
Available for sale, Gross Unrealized Losses Less than 12 months	5	13
Available for sale, Fair Value 12 months or longer	469	989
Available for sale, Gross Unrealized Losses 12 months or longer	14	48
Available for sale, Fair Value Total	1,365	1,628
Available for sale, Gross Unrealized Losses Total	19	61
Held to maturity, Fair Value Less than 12 months	580	'
Held to maturity, Gross Unrealized Losses Less than 12 months	3	'
Held to maturity, Fair Value 12 months or longer	0	'
Held to maturity, Gross Unrealized Losses 12 months or longer	0	'
Held to maturity, Fair Value Total	580	'
Held to maturity, Gross Unrealized Losses Total	3	'
Total non-U.S. debt securities	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	3,382	2,152
Available for sale, Gross Unrealized Losses Less than 12 months	18	5
Available for sale, Fair Value 12 months or longer	263	506
Available for sale, Gross Unrealized Losses 12 months or longer	12	27
Available for sale, Fair Value Total	3,645	2,658
Available for sale, Gross Unrealized Losses Total	30	32
Held to maturity, Fair Value Less than 12 months	1,872	56
Held to maturity, Gross Unrealized Losses Less than 12 months	7	1
Held to maturity, Fair Value 12 months or longer	893	1,185
Held to maturity, Gross Unrealized Losses 12 months or longer	62	70
Held to maturity, Fair Value Total	2,765	1,241
Held to maturity, Gross Unrealized Losses Total	69	71
Non-U.S. debt securities, mortgage-backed securities	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	1,240	670
Available for sale, Gross Unrealized Losses Less than 12 months	3	3
Available for sale, Fair Value 12 months or longer	242	453
Available for sale, Gross Unrealized Losses 12 months or longer	10	24
Available for sale, Fair Value Total	1,482	1,123
Available for sale, Gross Unrealized Losses Total	13	27
Held to maturity, Fair Value Less than 12 months	1,155	56
Held to maturity, Gross Unrealized Losses Less than 12 months	5	1
Held to maturity, Fair Value 12 months or longer	893	956
Held to maturity, Gross Unrealized Losses 12 months or longer	62	67
Held to maturity, Fair Value Total	2,048	1,012
Held to maturity, Gross Unrealized Losses Total	67	68
Non-U.S. debt securities, asset-backed securities	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	708	973
Available for sale, Gross Unrealized Losses Less than 12 months	1	1
Available for sale, Fair Value 12 months or longer	21	53
Available for sale, Gross Unrealized Losses 12 months or longer	2	3
Available for sale, Fair Value Total	729	1,026
Available for sale, Gross Unrealized Losses Total	3	4
Held to maturity, Fair Value Less than 12 months	717	0
Held to maturity, Gross Unrealized Losses Less than 12 months	2	0
Held to maturity, Fair Value 12 months or longer	0	73
Held to maturity, Gross Unrealized Losses 12 months or longer	0	1
Held to maturity, Fair Value Total	717	73
Held to maturity, Gross Unrealized Losses Total	2	1
Non-U.S. debt securities, other	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	1,434	509
Available for sale, Gross Unrealized Losses Less than 12 months	14	1
Available for sale, Fair Value 12 months or longer	0	0
Available for sale, Gross Unrealized Losses 12 months or longer	0	0
Available for sale, Fair Value Total	1,434	509
Available for sale, Gross Unrealized Losses Total	14	1
Held to maturity, Fair Value Less than 12 months	'	0
Held to maturity, Gross Unrealized Losses Less than 12 months	'	0
Held to maturity, Fair Value 12 months or longer	'	156
Held to maturity, Gross Unrealized Losses 12 months or longer	'	2
Held to maturity, Fair Value Total	'	156
Held to maturity, Gross Unrealized Losses Total	'	2
State and political subdivisions	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	2,436	685
Available for sale, Gross Unrealized Losses Less than 12 months	118	9
Available for sale, Fair Value 12 months or longer	1,080	1,152
Available for sale, Gross Unrealized Losses 12 months or longer	62	58
Available for sale, Fair Value Total	3,516	1,837
Available for sale, Gross Unrealized Losses Total	180	67
Collateralized mortgage obligations	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	1,665	347
Available for sale, Gross Unrealized Losses Less than 12 months	65	1
Available for sale, Fair Value 12 months or longer	304	621
Available for sale, Gross Unrealized Losses 12 months or longer	8	14
Available for sale, Fair Value Total	1,969	968
Available for sale, Gross Unrealized Losses Total	73	15
Held to maturity, Fair Value Less than 12 months	905	120
Held to maturity, Gross Unrealized Losses Less than 12 months	27	1
Held to maturity, Fair Value 12 months or longer	96	153
Held to maturity, Gross Unrealized Losses 12 months or longer	4	11
Held to maturity, Fair Value Total	1,001	273
Held to maturity, Gross Unrealized Losses Total	31	12
Other U.S.debt securities	'	'
Gross Pre-Tax Unrealized Losses On Investment Securities [Line Items]	'	'
Available for sale, Fair Value Less than 12 months	1,047	302
Available for sale, Gross Unrealized Losses Less than 12 months	27	1
Available for sale, Fair Value 12 months or longer	33	33
Available for sale, Gross Unrealized Losses 12 months or longer	6	6
Available for sale, Fair Value Total	1,080	335
Available for sale, Gross Unrealized Losses Total	$33	$7

Investment_Securities_Schedule2

Investment Securities (Schedule of Contractual Maturities of Debt Securities) (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	$9,647
Available for sale, 1 to 5 Years	37,558
Available for sale, 6 to 10 Years	21,022
Available for sale, Over 10 Years	30,860
Held to maturity, Under 1 Year	427
Held to maturity, 1 to 5 Years	4,302
Held to maturity, 6 to 10 Years	6,679
Held to maturity, Over 10 Years	5,290
Total asset-backed securities	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	4,305
Available for sale, 1 to 5 Years	11,805
Available for sale, 6 to 10 Years	8,281
Available for sale, Over 10 Years	5,273
Held to maturity, Under 1 Year	19
Held to maturity, 1 to 5 Years	892
Held to maturity, 6 to 10 Years	823
Held to maturity, Over 10 Years	1,117
US Treasury and federal agencies, direct obligations	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	0
Available for sale, 1 to 5 Years	42
Available for sale, 6 to 10 Years	46
Available for sale, Over 10 Years	650
Held to maturity, Under 1 Year	0
Held to maturity, 1 to 5 Years	0
Held to maturity, 6 to 10 Years	5,000
Held to maturity, Over 10 Years	3
US Treasury and federal agencies, mortgage-backed securities	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	103
Available for sale, 1 to 5 Years	1,847
Available for sale, 6 to 10 Years	6,188
Available for sale, Over 10 Years	16,437
Held to maturity, Under 1 Year	0
Held to maturity, 1 to 5 Years	25
Held to maturity, 6 to 10 Years	19
Held to maturity, Over 10 Years	56
Asset-backed securities, student loans	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	1,019
Available for sale, 1 to 5 Years	6,513
Available for sale, 6 to 10 Years	4,646
Available for sale, Over 10 Years	2,693
Held to maturity, Under 1 Year	19
Held to maturity, 1 to 5 Years	153
Held to maturity, 6 to 10 Years	219
Held to maturity, Over 10 Years	1,111
Asset-backed securities, credit cards	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	2,919
Available for sale, 1 to 5 Years	3,506
Available for sale, 6 to 10 Years	2,201
Available for sale, Over 10 Years	0
Held to maturity, Under 1 Year	0
Held to maturity, 1 to 5 Years	229
Held to maturity, 6 to 10 Years	302
Held to maturity, Over 10 Years	0
Asset-backed securities, sub-prime	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	26
Available for sale, 1 to 5 Years	28
Available for sale, 6 to 10 Years	2
Available for sale, Over 10 Years	1,210
Asset-backed securities, other	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	341
Available for sale, 1 to 5 Years	1,758
Available for sale, 6 to 10 Years	1,432
Available for sale, Over 10 Years	1,370
Held to maturity, Under 1 Year	0
Held to maturity, 1 to 5 Years	510
Held to maturity, 6 to 10 Years	302
Held to maturity, Over 10 Years	6
Total non-U.S. debt securities	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	4,085
Available for sale, 1 to 5 Years	14,788
Available for sale, 6 to 10 Years	1,082
Available for sale, Over 10 Years	4,654
Held to maturity, Under 1 Year	258
Held to maturity, 1 to 5 Years	2,198
Held to maturity, 6 to 10 Years	335
Held to maturity, Over 10 Years	3,010
Non-U.S. debt securities, mortgage-backed securities	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	148
Available for sale, 1 to 5 Years	6,191
Available for sale, 6 to 10 Years	159
Available for sale, Over 10 Years	4,503
Held to maturity, Under 1 Year	0
Held to maturity, 1 to 5 Years	939
Held to maturity, 6 to 10 Years	164
Held to maturity, Over 10 Years	3,006
Non-U.S. debt securities, asset-backed securities	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	253
Available for sale, 1 to 5 Years	4,685
Available for sale, 6 to 10 Years	378
Available for sale, Over 10 Years	151
Held to maturity, Under 1 Year	80
Held to maturity, 1 to 5 Years	1,235
Held to maturity, 6 to 10 Years	171
Held to maturity, Over 10 Years	0
Non-US debt securities, government securities	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	2,541
Available for sale, 1 to 5 Years	1,000
Available for sale, 6 to 10 Years	0
Available for sale, Over 10 Years	0
Held to maturity, Under 1 Year	16
Held to maturity, 1 to 5 Years	0
Held to maturity, 6 to 10 Years	0
Held to maturity, Over 10 Years	0
Non-U.S. debt securities, other	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	1,143
Available for sale, 1 to 5 Years	2,912
Available for sale, 6 to 10 Years	545
Available for sale, Over 10 Years	0
Held to maturity, Under 1 Year	162
Held to maturity, 1 to 5 Years	24
Held to maturity, 6 to 10 Years	0
Held to maturity, Over 10 Years	4
State and political subdivisions	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	668
Available for sale, 1 to 5 Years	3,059
Available for sale, 6 to 10 Years	3,565
Available for sale, Over 10 Years	2,006
Held to maturity, Under 1 Year	48
Held to maturity, 1 to 5 Years	13
Held to maturity, 6 to 10 Years	0
Held to maturity, Over 10 Years	0
Collateralized mortgage obligations	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	271
Available for sale, 1 to 5 Years	1,923
Available for sale, 6 to 10 Years	1,157
Available for sale, Over 10 Years	1,807
Held to maturity, Under 1 Year	102
Held to maturity, 1 to 5 Years	1,174
Held to maturity, 6 to 10 Years	502
Held to maturity, Over 10 Years	1,104
Other U.S.debt securities	'
Contractual Maturities Of Debt Investment Securities [Line Items]	'
Available for sale, Under 1 Year	215
Available for sale, 1 to 5 Years	4,094
Available for sale, 6 to 10 Years	703
Available for sale, Over 10 Years	$33

Investment_Securities_Gains_an

Investment Securities (Gains and Losses Related to Investment Securities) (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'		'		'		'
Gross realized gains from sales of available-for-sale securities	$11		$24		$98		$75		'
Gross realized losses from sales of available-for-sale securities	-5	[1]	0	[1]	-87	[1]	-46	[1]	'
Gross losses from other-than-temporary impairment	-8		-4		-8		-50		'
Losses reclassified (from) to other comprehensive income	-2		-2		-12		23		'
Gains (losses) related to investment securities, net	-4		18		-9		2		'
Impairment associated with expected credit losses	-8		-1		-8		-14		'
Impairment associated with management's intent to sell impaired securities prior to recovery in value	0		0		-6		0		'
Impairment associated with adverse changes in timing of expected future cash flows	-2		-5		-6		-13		'
Net impairment losses recognized in consolidated statement of income	10		6		20		27		'
Available for sale, amortized cost	99,747		'		99,747		'		108,563
GREECE	'		'		'		'		'
Available-For-Sale and Held-To-Maturity-Securities [Line Items]	'		'		'		'		'
Available for sale, amortized cost	'		$91		'		$91		'
[1]	Amount for the nine months ended September 30, 2012 represented a pre-tax loss from the sale of all of our Greek investment securities, which had an aggregate carrying value of approximately $91 million.

Investment_Securities_Schedule3

Investment Securities (Schedule of Credit-Related Loss Activity Recognized In Earnings) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]	'	'
Beginning balance	$124	$113
Plus losses for which other-than-temporary impairment was not previously recognized	14	2
Plus losses for which other-than-temporary impairment was previously recognized	6	25
Less previously recognized losses related to securities sold or matured	-10	-21
Ending balance	$134	$119

Loans_and_Leases_Narrative_Det

Loans and Leases (Narrative) (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]	'	'
Loans and leases, allowance for losses	$22,000,000	$22,000,000
Aggregate short-duration advances	4,650,000,000	3,300,000,000
Loans modified in troubled debt restructurings	0	0
Commercial and Financial	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Loans and leases, allowance for losses	0	'
Institutional	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Amount of loan losses related to institutional loans collectively evaluated for impairment	22,000,000	22,000,000
Institutional | Senior Secured Bank Loans	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial and financial	375,000,000	0
Commercial Real Estate	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Amount of loan losses related to institutional loans collectively evaluated for impairment	22,000,000	22,000,000
Loan modification, recorded investment	130,000,000	197,000,000
Impairment loss recognized	$0	$0

Loans_and_Leases_Net_Loans_Det

Loans and Leases (Net Loans) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loans and leases	$15,578	$12,307
Allowance for loan losses	-22	-22
Loans and leases, net of allowance for loan losses	15,556	12,285
Commercial Real Estate	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loans and leases	166	411
Institutional	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Total loans and leases	15,412	11,896
U.S. | Commercial Real Estate	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Commercial real estate	166	411
U.S. | Institutional	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Investment funds	10,017	8,376
Commercial and financial	1,486	613
Purchased receivables	231	276
Lease financing	357	380
Non-U.S. | Institutional	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Investment funds	1,998	829
Commercial and financial	509	520
Purchased receivables	60	118
Lease financing	$754	$784

Loans_and_Leases_Recorded_Inve

Loans and Leases (Recorded Investment in Each Class of Total Loans and Leases by Credit Quality Indicator) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	$15,578		$12,307
Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	15,412		11,896
Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	166		411
Investment Funds | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	12,015		9,205
Commercial and Financial | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	1,995		1,133
Purchased Receivables | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	291		394
Lease Financing | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	1,111		1,164
Property Development | Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	137		377
Other | Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	29		34
Investment grade	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	14,429		11,538	[1]
Investment grade | Investment Funds | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	11,574		8,937	[1]
Investment grade | Commercial and Financial | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	1,456		1,041	[1]
Investment grade | Purchased Receivables | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	291		394	[1]
Investment grade | Lease Financing | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	1,079		1,137	[1]
Investment grade | Property Development | Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	0		0	[1]
Investment grade | Other | Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	29		29	[1]
Speculative	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	1,129		769	[2]
Speculative | Investment Funds | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	441		268	[2]
Speculative | Commercial and Financial | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	519		92	[2]
Speculative | Purchased Receivables | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	0		0	[2]
Speculative | Lease Financing | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	32		27	[2]
Speculative | Property Development | Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	137		377	[2]
Speculative | Other | Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	0		5	[2]
Special mention	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	20	[3]	'
Special mention | Investment Funds | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	0	[3]	'
Special mention | Commercial and Financial | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	20	[3]	'
Special mention | Purchased Receivables | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	0	[3]	'
Special mention | Lease Financing | Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	0	[3]	'
Special mention | Property Development | Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	0	[3]	'
Special mention | Other | Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Total Loans and Leases	$0	[3]	'
[1]	Investment grade loans and leases consist of counterparties with strong credit quality and low expected credit risk and probability of default. Ratings apply to counterparties with a strong capacity to support the timely repayment of any financial commitment.
[2]	Speculative loans and leases consist of counterparties that face ongoing uncertainties or exposure to business, financial, or economic downturns. However, these counterparties may have financial flexibility or access to financial alternatives, which allow for financial commitments to be met.
[3]	Special mention loans and leases consist of counterparties with potential weaknesses that, if uncorrected, may result in deterioration of repayment prospects.

Loans_and_Leases_Schedule_of_A

Loans and Leases (Schedule of Allowance for Loan Losses) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Loans and leases, Individually evaluated for impairment	$542		$422
Loans and leases, Collectively evaluated for impairment	15,036	[1]	11,885	[1]
Total loans and leases	15,578		12,307
Institutional	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Loans and leases, Individually evaluated for impairment	405		11
Loans and leases, Collectively evaluated for impairment	15,007	[1]	11,885	[1]
Total loans and leases	15,412		11,896
Commercial Real Estate	'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'
Loans and leases, Individually evaluated for impairment	137		411
Loans and leases, Collectively evaluated for impairment	29	[1]	0	[1]
Total loans and leases	$166		$411
[1]	As of both September 30, 2013 and December 31, 2012, the entire $22 million allowance for loan losses was related to institutional loans collectively evaluated for impairment.

Loans_and_Leases_Impaired_Loan

Loans and Leases (Impaired Loans) (Details) (Commercial Real Estate, USD $)	3 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]	'		'	'		'	'
Recorded investment with no related allowance	$130		'	$130		'	$197
Unpaid principal balance with no related allowance recorded	198		'	198		'	322
Related allowance	0	[1]	'	0	[1]	'	0	[1]
Additional allowance for loan losses	22		'	22		'	22
Average recorded investment	130		204	160		216	'
Interest revenue recognized	2		4	17		12	'
CRE - property development	'		'	'		'	'
Financing Receivable, Impaired [Line Items]	'		'	'		'	'
Recorded investment with no related allowance	130		'	130		'	197
Unpaid principal balance with no related allowance recorded	143		'	143		'	224
Related allowance	0	[1]	'	0	[1]	'	0	[1]
Average recorded investment	130		199	160		199	'
Interest revenue with related allowance recognized	2		4	17		12	'
CRE - property development - acquired credit impaired	'		'	'		'	'
Financing Receivable, Impaired [Line Items]	'		'	'		'	'
Recorded investment with no related allowance	0		'	0		'	0
Unpaid principal balance with no related allowance recorded	34		'	34		'	34
Related allowance	0	[1]	'	0	[1]	'	0	[1]
CRE - other - acquired credit impaired	'		'	'		'	'
Financing Receivable, Impaired [Line Items]	'		'	'		'	'
Recorded investment with no related allowance	0		'	0		'	0
Unpaid principal balance with no related allowance recorded	21		'	21		'	64
Related allowance	0	[1]	'	0	[1]	'	0	[1]
Average recorded investment	0		5	0		17	'
Interest revenue with related allowance recognized	0		0	0		0	'
Recorded investment with related allowance	0		0	0		0	'
Interest revenue with no related allowance recognized	$0		$0	$0		$0	'
[1]	As of both September 30, 2013 and December 31, 2012, we maintained an allowance for loan losses of $22 million associated with loans and leases that were not impaired.

Loans_and_Leases_Schedule_of_A1

Loans and Leases (Schedule of Activity In The Allowance For Loan Losses) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Allowance for Loan and Lease Losses [Roll Forward]	'	'	'	'
Beginning balance	$22	$22	$22	$22
Provisions	0	0	0	-1
Recoveries	0	0	0	1
Ending balance	22	22	22	22
Institutional	'	'	'	'
Allowance for Loan and Lease Losses [Roll Forward]	'	'	'	'
Beginning balance	22	22	22	22
Provisions	0	0	0	0
Recoveries	0	0	0	0
Ending balance	22	22	22	22
Commercial Real Estate	'	'	'	'
Allowance for Loan and Lease Losses [Roll Forward]	'	'	'	'
Beginning balance	0	0	0	0
Provisions	0	0	0	-1
Recoveries	0	0	0	1
Ending balance	$0	$0	$0	$0

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets (Changes In The Carrying Amount Of Goodwill) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Goodwill [Roll Forward]	'	'
Beginning balance	$5,977	$5,645
Divestitures	-7	0
Foreign currency translation, net	36	5
Ending balance	6,006	5,650
Investment Servicing	'	'
Goodwill [Roll Forward]	'	'
Beginning balance	5,941	5,610
Divestitures	-7	0
Foreign currency translation, net	35	5
Ending balance	5,969	5,615
Investment Management	'	'
Goodwill [Roll Forward]	'	'
Beginning balance	36	35
Divestitures	0	0
Foreign currency translation, net	1	0
Ending balance	$37	$35

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets (Changes In The Carrying Amount Of Other Intangible Assets) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Finite-lived Intangible Assets [Roll Forward]	'	'	'	'
Beginning balance	'	'	$2,539	$2,459
Divestitures	'	'	-5	0
Amortization	-53	-46	-160	-145
Foreign currency translation, net	'	'	22	-3
Ending balance	2,396	2,311	2,396	2,311
Investment Servicing	'	'	'	'
Finite-lived Intangible Assets [Roll Forward]	'	'	'	'
Beginning balance	'	'	2,492	2,408
Divestitures	'	'	-5	0
Amortization	'	'	-153	-143
Foreign currency translation, net	'	'	22	-3
Ending balance	2,356	2,262	2,356	2,262
Investment Management	'	'	'	'
Finite-lived Intangible Assets [Roll Forward]	'	'	'	'
Beginning balance	'	'	47	51
Divestitures	'	'	0	0
Amortization	'	'	-7	-2
Foreign currency translation, net	'	'	0	0
Ending balance	$40	$49	$40	$49

Goodwill_and_Other_Intangible_4

Goodwill and Other Intangible Assets (Gross Carrying Amount, Accumulated Amortization And Net Carrying Amount Of Other Intangible Assets) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Gross Carrying Amount	$3,629	$3,603	'	'
Accumulated Amortization	-1,233	-1,064	'	'
Net Carrying Amount	2,396	2,539	2,311	2,459
Client relationships	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Gross Carrying Amount	2,669	2,653	'	'
Accumulated Amortization	-917	-755	'	'
Net Carrying Amount	1,752	1,898	'	'
Core deposits	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Gross Carrying Amount	712	706	'	'
Accumulated Amortization	-180	-192	'	'
Net Carrying Amount	532	514	'	'
Other	'	'	'	'
Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Gross Carrying Amount	248	244	'	'
Accumulated Amortization	-136	-117	'	'
Net Carrying Amount	$112	$127	'	'

Other_Assets_and_Other_Liabili2

Other Assets and Other Liabilities (Components of Other Assets) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
Other Assets [Line Items]	'		'
Total	$23,357,000,000		$18,016,000,000
Real estate acquired through foreclosure	58,000,000		65,000,000
Accrued expenses and other liabilities	'		'
Other Assets [Line Items]	'		'
Cash collateral received in connection to securities finance activities	6,390,000,000		4,990,000,000
Reported Amount | Other assets	'		'
Other Assets [Line Items]	'		'
Collateral deposits, net	12,106,000,000		7,649,000,000
Unrealized gains on derivative financial instruments, net	4,320,000,000		4,556,000,000
Bank-owned life insurance	2,027,000,000		2,000,000,000
Investments in joint ventures and other unconsolidated entities	1,466,000,000		1,405,000,000
Accounts receivable	1,109,000,000		511,000,000
Receivable for securities settlement	358,000,000		33,000,000
Deferred tax assets, net of valuation allowance	302,000,000		353,000,000
Prepaid expenses	299,000,000		267,000,000
Income taxes receivable	261,000,000		252,000,000
Deposits with clearing organizations	179,000,000		174,000,000
Receivable for securities sold	92,000,000		1,000,000
Other	838,000,000	[1]	815,000,000	[1]
Total	$23,357,000,000		$18,016,000,000
[1]	Included other real estate owned of approximately $58 million and $65 million, respectively.

LongTerm_Debt_Narrative_Detail

Long-Term Debt (Narrative) (Details) (USD $)	31-May-13
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'
Debt Instrument, Face Amount	$1,500
Senior notes | 1.35% due May, 15 2018	'
Debt Instrument [Line Items]	'
Debt Instrument, Face Amount	500
Senior notes interest rate percentage	1.35%
Subordinated note | 3.1% due May, 15 2023	'
Debt Instrument [Line Items]	'
Debt Instrument, Face Amount	$1,000
Senior notes interest rate percentage	3.10%

Commitments_Guarantees_and_Con2

Commitments, Guarantees, and Contingencies (Narrative) (Details) (USD $)

9 Months Ended

0 Months Ended

1 Months Ended

9 Months Ended

12 Months Ended

108 Months Ended

Sep. 30, 2013

Dec. 31, 2012

Aug. 31, 2009

Sep. 30, 2013

Aug. 31, 2009

Sep. 30, 2013

Jun. 30, 2013

Sep. 30, 2010

Oct. 31, 2010

Sep. 30, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

Dec. 31, 2009

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jun. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

customer

State Street Global Advisors

Securities Finance

Securities Finance

Securities Finance

Securities Finance

Foreign Exchange

Foreign Exchange

Foreign Exchange

Foreign Exchange

Foreign Exchange

Foreign Exchange

Foreign Exchange

Foreign Exchange

Shareholder Litigation

Transition Management

Investment Servicing

Investment Servicing

Accrued expenses and other liabilities

Accrued expenses and other liabilities

Minimum

Maximum

claim

shareholder

Legal Reserve

Legal Reserve

Legal Reserve

State Street Global Advisors

State Street Global Advisors

complaint

Loss Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unfunded commitments to extend credit

$19,980,000,000

$17,860,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unfunded commitments to extend credit, short term

75.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percent of fair market value that must be maintained in collateral

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash collateral provided for securities lending

9,760,000,000

6,830,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash collateral received in connection to securities finance activities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

6,390,000,000

4,990,000,000

'

'

Number of pending claims

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Alleged excess fees paid

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

145,000,000

237,000,000

Number of suits from related participants of agency securities lending program

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss contingency, damages sought, value

'

'

'

'

120,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

The difference between the amortized cost and market value of the in-kind distribution

'

'

'

'

'

'

'

49,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Realized loss on sales of securities

'

'

'

'

'

'

11,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Litigation reserve

'

'

'

15,000,000

'

10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Actual damages asserted by attorney general

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100,000,000

'

'

'

'

'

'

'

'

Settlement, amount

'

'

'

'

'

'

'

'

12,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated indirect foreign exchange revenue

'

'

'

'

'

'

'

'

'

223,000,000

248,000,000

331,000,000

336,000,000

369,000,000

462,000,000

'

'

'

'

'

'

'

'

'

Shareholder related class action complaints pending in Boston Federal Court

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3

'

'

'

'

'

'

'

Number of class action complaints pending in Boston Federal Court brought on behalf of State Street shareholders

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

Number of class action complaints pending in Boston Federal Court brought on behalf of State Street participants and benficiaries of State Street Salary Savings Program

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

Legal reserves

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13,400,000

6,500,000

9,000,000

'

'

'

'

Unrecognized tax benefits

$116,000,000

$95,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commitments_Guarantees_and_Con3

Commitments, Guarantees, and Contingencies (Contractual Amounts of Credit-Related Off-Balance Sheet Financial Instruments) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'	'
Indemnified securities financing	$315,632	$302,341
Stable value protection	27,913	33,512
Asset purchase agreements	4,646	5,063
Standby letters of credit	$4,601	$4,552

Commitments_Guarantees_and_Con4

Commitments, Guarantees, and Contingencies (Schedule Of Repurchase Agreements) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'	'
Aggregate fair value of indemnified securities financing	$315,632	$302,341
Aggregate fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing	327,567	312,223
Aggregate fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements	86,461	80,224
Aggregate fair value of cash and securities held by us or our agents as collateral for investments in indemnified repurchase agreements	$91,884	$85,411

Variable_Interest_Entities_Det

Variable Interest Entities (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Variable Interest Entities [Abstract]	'	'
Investment securities related to state and political subdivisions	$2,380,000,000	$2,680,000,000
Variable interest entity, other short-term borrowings	1,980,000,000	2,150,000,000
Weighted average life of trusts (in years)	'6 years 8 months	'6 years 11 months
Total standby bond-purchase agreement committed to trusts	2,020,000,000	'
Letters of credit amounts outstanding	691,000,000	'
Standby purchase agreements and letters of credit commitments utlized	0	'
Potential maximum loss exposure of unconsolidated funds	$18,000,000	$28,000,000

Shareholders_Equity_Narrative_

Shareholders' Equity (Narrative) (Details) (USD $)

3 Months Ended

9 Months Ended

12 Months Ended

1 Months Ended

3 Months Ended

6 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Dec. 31, 2011

Mar. 31, 2013

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2012

March 2013 Repurchase Program

March 2013 Repurchase Program

March 2013 Repurchase Program

March 2013 Repurchase Program

March 2013 Repurchase Program

March 2012 Share Repurchase Program

Retained Earnings

Retained Earnings

Retained Earnings

Retained Earnings

Series C Preferred Stock

Series C Preferred Stock

Series C Preferred Stock

Series C Preferred Stock

Depositary Shares

Depositary Shares

Series A Preferred Stock

Series A Preferred Stock

Equity, Class of Treasury Stock [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount of common stock authorized for repurchase

'

'

'

'

'

'

$2,100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock acquired (shares)

'

'

23,200,000

'

'

'

'

8,200,000

0

16,700,000

'

6,500,000

'

'

'

'

'

'

'

'

'

'

'

'

Remaining authorized repurchase amount

'

'

'

'

'

'

'

'

'

'

980,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Average cost per share of treasury shares repurchased (per share)

'

'

$63.69

'

'

'

'

$68.57

'

$67.12

'

$54.95

'

'

'

'

'

'

'

'

'

'

'

'

Approximate aggregate cost of treasury shares repurchased

'

'

1,480,000,000

'

'

'

'

560,000,000

'

1,120,000,000

'

360,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Cash dividends declared (in dollars per share)

$0.26

$0.24

$0.78

$0.72

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock dividends

'

'

350,000,000

346,000,000

'

'

'

'

'

'

'

'

115,000,000

113,000,000

350,000,000

346,000,000

'

'

'

'

'

'

'

'

Depositary shares, ownership interest

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.03%

'

'

'

'

'

'

'

Preferred stock dividends (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$1,312.50

'

$3,937.50

'

$0.33

$0.98

'

'

Dividends, Preferred Stock, Cash

'

'

20,000,000

29,000,000

'

'

'

'

'

'

'

'

'

'

20,000,000

29,000,000

7,000,000

8,000,000

20,000,000

8,000,000

'

'

7,000,000

21,000,000

Realized gains (losses) from sale of available-for-sale securities

'

'

'

29,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net gains (losses) from sales of available-for-sale securities

'

'

11,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrealized pretax gains (losses) on securities included in AOCI

'

'

'

'

25,000,000

22,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred taxes on unrealized pretax gains (losses) on securities included in AOCI

'

'

'

'

$10,000,000

$9,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shareholders_Equity_Schedule_O

Shareholders' Equity (Schedule Of Accumulated Other Comprehensive (Loss) Income) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Stockholders' Equity Note [Abstract]	'	'
Net unrealized gains on cash flow hedges	$130	$69
Net unrealized gains on available-for-sale securities portfolio	138	815
Net unrealized losses related to reclassified available-for-sale securities	-81	-110
Net unrealized gains on available-for-sale securities	57	705
Net unrealized losses on available-for-sale securities designated in fair value hedges	-122	-183
Other-than-temporary impairment on available-for-sale securities related to factors other than credit	3	-3
Net unrealized losses on hedges of net investments in non-U.S. subsidiaries	-14	-14
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit	-51	-65
Net unrealized losses on retirement plans	-274	-283
Foreign currency translation	157	134
Total	($114)	$360

Shareholders_Equity_Accumulate

Shareholders' Equity (Accumulated Other Comprehensive Income by Component) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]	'	'	'	'
AOCI net of tax, beginning balance	'	'	$360	'
Other comprehensive income (loss) before reclassifications	'	'	-492	'
Amounts reclassified out of AOCI	'	'	18	'
Other comprehensive income (loss)	409	723	-474	845
AOCI net of tax, ending balance	-114	'	-114	'
Net Unrealized Gains (Losses) on Cash Flow Hedges	'	'	'	'
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]	'	'	'	'
AOCI net of tax, beginning balance	'	'	69	'
Other comprehensive income (loss) before reclassifications	'	'	59	'
Amounts reclassified out of AOCI	'	'	2	'
Other comprehensive income (loss)	'	'	61	'
AOCI net of tax, ending balance	130	'	130	'
Net Unrealized Gains (Losses) on Available-for-Sale Securities	'	'	'	'
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]	'	'	'	'
AOCI net of tax, beginning balance	'	'	519	'
Other comprehensive income (loss) before reclassifications	'	'	-578	'
Amounts reclassified out of AOCI	'	'	-3	'
Other comprehensive income (loss)	'	'	-581	'
AOCI net of tax, ending balance	-62	'	-62	'
Net Unrealized Losses on Hedges of Net Investments in Non-U.S. Subsidiaries	'	'	'	'
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]	'	'	'	'
AOCI net of tax, beginning balance	'	'	-14	'
Other comprehensive income (loss) before reclassifications	'	'	0	'
Amounts reclassified out of AOCI	'	'	0	'
Other comprehensive income (loss)	'	'	0	'
AOCI net of tax, ending balance	-14	'	-14	'
Other-Than-Temporary Impairment on Held-to-Maturity Securities	'	'	'	'
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]	'	'	'	'
AOCI net of tax, beginning balance	'	'	-65	'
Other comprehensive income (loss) before reclassifications	'	'	11	'
Amounts reclassified out of AOCI	'	'	3	'
Other comprehensive income (loss)	'	'	14	'
AOCI net of tax, ending balance	-51	'	-51	'
Net Unrealized Losses on Retirement Plans	'	'	'	'
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]	'	'	'	'
AOCI net of tax, beginning balance	'	'	-283	'
Other comprehensive income (loss) before reclassifications	'	'	-6	'
Amounts reclassified out of AOCI	'	'	15	'
Other comprehensive income (loss)	'	'	9	'
AOCI net of tax, ending balance	-274	'	-274	'
Foreign Currency Translation	'	'	'	'
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]	'	'	'	'
AOCI net of tax, beginning balance	'	'	134	'
Other comprehensive income (loss) before reclassifications	'	'	22	'
Amounts reclassified out of AOCI	'	'	1	'
Other comprehensive income (loss)	'	'	23	'
AOCI net of tax, ending balance	$157	'	$157	'

Shareholders_Equity_Adjustment

Shareholders' Equity (Adjustments to Accumulated Other Comprehensive Income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Class of Stock [Line Items]	'	'	'	'
Net interest revenue	$546	$619	$1,718	$1,916
Net gains (losses) from sales of available-for-sale securities	'	'	11	'
Processing fees and other revenue	326	172	23	19
Total reclassifications out of AOCI	531	654	1,557	1,551
Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Class of Stock [Line Items]	'	'	'	'
Total reclassifications out of AOCI	2	'	18	'
Net Unrealized Gains (Losses) on Cash Flow Hedges | Interest-rate contracts | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Class of Stock [Line Items]	'	'	'	'
Net interest revenue	0	'	2	'
Interest-rate contracts, tax	1	'	1	'
Net Unrealized Gains (Losses) on Available-for-Sale Securities | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Class of Stock [Line Items]	'	'	'	'
Net gains (losses) from sales of available-for-sale securities	-4	'	-7	'
Net realized gasin from sales of available-for-sale securities, tax	-2	'	-4	'
Other-Than-Temporary Impairment on Held-to-Maturity Securities | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Class of Stock [Line Items]	'	'	'	'
Available-for-sale securities, Losses reclassified (from) to other comprehensive income	0	'	4	'
Held-to-maturity securities, Losses reclassified (from) to other comprehensive income	1	'	3	'
Other-than-temporary impairment on available-for-sale securities related to factors other than credit, tax	2	'	2	'
Other-than-temporary impairment on available-for-sale securities related to factors other than credit, tax	1	'	3	'
Net Unrealized Losses on Retirement Plans | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Class of Stock [Line Items]	'	'	'	'
Compensation and employee benefits expense	5	'	15	'
Amortization of actuarial loses, tax	3	'	9	'
Foreign Currency Translation | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Class of Stock [Line Items]	'	'	'	'
Processing fees and other revenue	0	'	1	'
Sale foreign entites, tax	$1	'	$1	'

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Narrative) (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2013		Dec. 31, 2012
Derivative [Line Items]	'		'
Cash collateral received for derivative instruments	$2,870,000,000		$1,680,000,000
Cash collateral provided for derivative instruments	2,800,000,000		1,300,000,000
Fair value of derivative liabilities	10,577,000,000	[1]	9,438,000,000	[1]
Weighted average life of trusts (in years)	'6 years 8 months		'6 years 11 months
Credit swap agreements	'		'
Derivative [Line Items]	'		'
Fair value of derivative liabilities	421,000,000		'
Carrying value of the underlying collateral	0		'
Maximum additional amount of payments related to termination events	$421,000,000		'
Fair Value Hedges | Interest rate swap | Senior notes	'		'
Derivative [Line Items]	'		'
Number of securities	1		'
Fair Value Hedges | Interest rate swap | Subordinated note	'		'
Derivative [Line Items]	'		'
Number of securities	1		'
Fair Value Hedges | 1.35% Senior Note	'		'
Derivative [Line Items]	'		'
Fixed interest rate	1.35%		'
Fair Value Hedges | 3.1% Subordinated Note | Interest rate swap	'		'
Derivative [Line Items]	'		'
Fixed interest rate	3.10%		'
Cash Flow Hedges	'		'
Derivative [Line Items]	'		'
Securities weighted average life (in years)	'1 year		'1 year 9 months
[1]	Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Schedule of Outstanding Hedges: (Notional Amount)) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	$4,222	$3,153
Swap agreements and forwards | Interest-rate contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	1,112	1,578
Options and caps purchased | Interest-rate contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	36	68
Options and caps written | Interest-rate contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	36	68
Futures | Interest-rate contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	5,126	1,910
Futures | Other contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	3	0
Forward, swap and spot | Foreign exchange contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	1,118,507	897,354
Options purchased | Foreign exchange contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	2,797	9,454
Options written | Foreign exchange contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	2,357	8,734
Credit swap agreements | Credit derivative contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	136	27
Stable value contracts | Other contracts | Derivatives not designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	27,913	33,512
Swap agreements | Interest-rate contracts | Derivatives designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	4,222	3,153
Forward and swap | Foreign exchange contracts | Derivatives designated as hedging instruments	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Notional amount of derivatives	$2,987	$3,477

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Notional Amount of Interest Rate Swap Agreements Designated as Fair Value and Cash Flow Hedges) (Details) (USD $)	9 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Derivative [Line Items]	'		'
Notional Amount of Fair Value Hedges	$4,092		$3,023
Notional Amount of Cash Flow Hedges	130		130
Notional amount of derivatives	4,222		3,153
Increase in carrying value of long-term debt	18		174
Investment securities available for sale	'		'
Derivative [Line Items]	'		'
Notional Amount of Fair Value Hedges	2,592		1,573
Notional Amount of Cash Flow Hedges	130		130
Notional amount of derivatives	2,722		1,703
Long-term debt	'		'
Derivative [Line Items]	'		'
Notional Amount of Fair Value Hedges	1,500	[1]	1,450	[1]
Notional Amount of Cash Flow Hedges	0	[1]	0	[1]
Notional amount of derivatives	$1,500	[1]	$1,450	[1]
[1]	As of September 30, 2013 and December 31, 2012, fair value hedges of long-term debt increased the carrying value of long-term debt presented in our consolidated statement of condition by $18 million and $174 million, respectively.

Derivative_Financial_Instrumen5

Derivative Financial Instruments (Contractual and Weighted-Average Interest Rates, Which Include the Effects of Hedges Related to Financial Instruments) (Details) (Long-term debt)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Long-term debt	'	'	'	'
Derivative [Line Items]	'	'	'	'
Contractual Rates	3.34%	4.13%	3.49%	4.01%
Rate Including Impact of Hedges	2.67%	3.20%	2.77%	3.20%

Derivative_Financial_Instrumen6

Derivative Financial Instruments (Schedule of The Fair Values of Derivative Financial Instruments) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	$10,425	[1]	$9,601	[1]
Fair value of derivative liabilities	10,577	[1]	9,438	[1]
Foreign exchange contracts	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	10,366	[1]	9,378	[1]
Fair value of derivative liabilities	10,261	[1]	9,084	[1]
Interest-rate contracts	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	58	[1]	223	[1]
Fair value of derivative liabilities	307	[1]	345	[1]
Derivatives not designated as hedging instruments | Other assets	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	10,144		9,304
Derivatives not designated as hedging instruments | Other liabilities	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative liabilities	10,254		9,137
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other assets	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	10,109		9,243
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other liabilities	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative liabilities	10,210		9,067
Derivatives not designated as hedging instruments | Interest-rate contracts | Other assets	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	34		61
Derivatives not designated as hedging instruments | Interest-rate contracts | Other liabilities	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative liabilities	35		61
Derivatives not designated as hedging instruments | Credit derivative contracts | Other assets	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	1		'
Derivatives not designated as hedging instruments | Other derivative contracts | Other assets	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	'		0
Derivatives not designated as hedging instruments | Other derivative contracts | Other liabilities	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative liabilities	9		9
Derivatives designated as hedging instruments | Other assets	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	281		297
Derivatives designated as hedging instruments | Other liabilities	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative liabilities	323		301
Derivatives designated as hedging instruments | Foreign exchange contracts | Other assets	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	257		135
Derivatives designated as hedging instruments | Foreign exchange contracts | Other liabilities	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative liabilities	51		17
Derivatives designated as hedging instruments | Interest-rate contracts | Other assets	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative assets	24		162
Derivatives designated as hedging instruments | Interest-rate contracts | Other liabilities	'		'
Derivatives, Fair Value [Line Items]	'		'
Fair value of derivative liabilities	$272		$284
[1]	Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.

Derivative_Financial_Instrumen7

Derivative Financial Instruments (Impact of Derivatives on Consolidated Statement of Income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivatives not designated as hedging instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	$148	$115	$465	$372
Derivatives designated as fair value hedges	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	0	47	-266	85
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	-1	-46	253	-85
Foreign exchange contracts | Trading services | Derivatives not designated as hedging instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	147	113	461	459
Foreign exchange contracts | Processing fees and other revenue | Derivatives not designated as hedging instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	0	1	0	-2
Foreign exchange contracts | Processing fees and other revenue | Derivatives designated as fair value hedges	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	20	26	-135	30
Foreign exchange contracts | Processing fees and other revenue | Investment securities [Member] | Derivatives designated as fair value hedges	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	-20	-26	135	-30
Interest-rate contracts | Trading services | Derivatives not designated as hedging instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	0	1	3	-87
Interest-rate contracts | Processing fees and other revenue | Derivatives not designated as hedging instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	0	0	0	2
Interest-rate contracts | Processing fees and other revenue | Contract one [Member] | Derivatives designated as fair value hedges	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	-14	-1	-146	-7
Interest-rate contracts | Processing fees and other revenue | Contract two [Member] | Derivatives designated as fair value hedges	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	-6	22	15	62
Interest-rate contracts | Processing fees and other revenue | Long-term debt | Derivatives designated as fair value hedges	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	12	1	133	3
Interest-rate contracts | Processing fees and other revenue | Investment securities available for sale | Derivatives designated as fair value hedges	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	7	-21	-15	-58
Credit derivative contracts | Processing fees and other revenue | Derivatives not designated as hedging instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	$1	$0	$1	$0

Derivative_Financial_Instrumen8

Derivative Financial Instruments (Schedule of Differences Between the Gains (Losses) on the Derivative and The Gains (Losses) on the Hedged Item) (Details) (Derivatives designed as cash flow value hedges, USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income	($56)	($2)	$108	$2
Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income	-1	-1	-3	-4
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	1	3	8	4
Interest-rate contracts	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income	-1	0	10	3
Interest-rate contracts | Net interest revenue	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income	-1	-1	-3	-4
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	1	1	3	2
Foreign exchange contracts	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) on Derivative Recognized in Other Comprehensive Income	-55	-2	98	-1
Foreign exchange contracts | Net interest revenue	'	'	'	'
Derivative [Line Items]	'	'	'	'
Amount of Gain (Loss) Reclassified from OCI to Consolidated Statement of Income	0	0	0	0
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	$0	$2	$5	$2

Offsetting_Arrangements_Assets

Offsetting Arrangements (Assets With Offsetting Arrangements) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Offsetting Assets [Line Items]	'		'
Derivatives, Gross Amounts of Recognized Assets	$10,425	[1]	$9,601	[1]
Derivatives, Gross Amounts Offset in Statement of Condition	-6,105	[2]	-5,045	[2]
Net Amounts of Assets Presented in Statement of Condition	4,320		4,556
Resale Agreements and Securities Borrowing, Gross Amounts of Recognized Assets	45,563	[1],[3]	35,658	[1],[3]
Resale Agreements and Securities Borrowing, Gross Amounts Offset in Statement of Condition	-29,974	[2],[3]	-23,809	[2],[3]
Net Amounts of Assets Presented in Statement of Condition	15,589	[3]	11,849	[3]
Total, Gross Amounts of Recognized Assets	55,988	[1]	45,259	[1]
Total, Gross Amounts Offset in Statement of Condition	-36,079	[2]	-28,854	[2]
Total, Net Amounts of Assets Presented in Statement of Condition	19,909		16,405
Securities purchased under resale agreements	5,827		5,016
Securities borrowed subject to master netting arrangements	9,762		6,833
Cash collateral netting	'		'
Offsetting Assets [Line Items]	'		'
Derivatives, Gross Amounts of Recognized Assets	0	[1]	0	[1]
Derivatives, Gross Amounts Offset in Statement of Condition	-2,303	[2]	-1,451	[2]
Net Amounts of Assets Presented in Statement of Condition	-2,303		-1,451
Interest-rate contracts	'		'
Offsetting Assets [Line Items]	'		'
Derivatives, Gross Amounts of Recognized Assets	58	[1]	223	[1]
Derivatives, Gross Amounts Offset in Statement of Condition	-45	[2]	-19	[2]
Net Amounts of Assets Presented in Statement of Condition	13		204
Foreign exchange contracts	'		'
Offsetting Assets [Line Items]	'		'
Derivatives, Gross Amounts of Recognized Assets	10,366	[1]	9,378	[1]
Derivatives, Gross Amounts Offset in Statement of Condition	-3,757	[2]	-3,575	[2]
Net Amounts of Assets Presented in Statement of Condition	6,609		5,803
Other derivative contracts	'		'
Offsetting Assets [Line Items]	'		'
Derivatives, Gross Amounts of Recognized Assets	1		0
Derivatives, Gross Amounts Offset in Statement of Condition	0		0
Net Amounts of Assets Presented in Statement of Condition	$1		$0
[1]	Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.
[2]	Amounts subject to netting arrangements which have been determined to be legally enforceable.
[3]	Included in the $15,589 million as of September 30, 2013 was $5,827 million of resale agreements and $9,762 million of collateral related to securities borrowing. Included in the $11,849 million as of December 31, 2012 was $5,016 million of resale agreements and $6,833 million of collateral related to securities borrowing. Resale agreements and collateral related to securities borrowing were recorded in securities purchased under resale agreements and other assets, respectively, in our consolidated statement of condition. Refer to note 8 for additional information with respect to principal securities finance transactions.

Offsetting_Arrangements_Assets1

Offsetting Arrangements (Assets With Enforceable Netting Arrangements) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Offsetting [Abstract]	'		'
Derivative, Net Amount of Assets Presented in Statement of Condition	$4,320		$4,556
Derivatives, Counterparty Netting	0	[1]	0	[1]
Derivatives, Collateral Received	-95	[1]	-105	[1]
Derivatives, Net Amount	4,225	[2]	4,451	[2]
Resale Agreements and Securities Borrowing, Resale Agreements and Securities Borrowing, Net Amount of Assets Presented in Statement of Condition	15,589	[3]	11,849	[3]
Resale Agreements and Securities Borrowing, Counterparty Netting	-144	[1]	-126	[1]
Resale Agreements and Securities Borrowing, Collateral Received	-15,360	[1]	-11,626	[1]
Resale Agreements and Securities Borrowing, Net Amount	85	[2]	97	[2]
Total, Net Amounts of Assets Presented in Statement of Condition	19,909		16,405
Total, Counterparty Netting	-144	[1]	-126	[1]
Total, Collateral Received	-15,455	[1]	-11,731	[1]
Total, Net Amount	$4,310	[2]	$4,548	[2]
[1]	Amounts subject to netting arrangements which have been determined to be legally enforceable
[2]	Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements.
[3]	Included in the $15,589 million as of September 30, 2013 was $5,827 million of resale agreements and $9,762 million of collateral related to securities borrowing. Included in the $11,849 million as of December 31, 2012 was $5,016 million of resale agreements and $6,833 million of collateral related to securities borrowing. Resale agreements and collateral related to securities borrowing were recorded in securities purchased under resale agreements and other assets, respectively, in our consolidated statement of condition. Refer to note 8 for additional information with respect to principal securities finance transactions.

Offsetting_Arrangements_Liabil

Offsetting Arrangements (Liabilities With Offsetting Arrangements) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Offsetting Liabilities [Line Items]	'		'
Gross Amounts of Recognized Liabilities	$10,577	[1]	$9,438	[1]
Gross Amounts Offset in Statement of Condition	-4,270	[1]	-4,071	[1],[2]
Net Amounts of Liabilities Presented in Statement of Condition	6,307	[1]	5,367	[1]
Gross Amounts of Recognized Liabilities	46,488	[1],[3]	36,801	[1],[3]
Gross Amounts Offset in Statement of Condition	-29,974	[2],[3]	-23,809	[2],[3]
Net Amounts of Liabilities Presented in Statement of Condition	16,514	[3]	12,992	[3]
Gross Amounts of Recognized Liabilities	57,065	[1]	46,239	[1]
Gross Amounts Offset in Statement of Condition	-34,244	[2]	-27,880	[2]
Total, Net Amount of Liabilities Presented in Statement of Condition	22,821		18,359
Securities sold under repurchase agreements	10,123		8,006
Securities Lending, Fair Value, Amount Not Offset Against Collateral	6,391		4,986
Interest-rate contracts	'		'
Offsetting Liabilities [Line Items]	'		'
Gross Amounts of Recognized Liabilities	307	[1]	345	[1]
Gross Amounts Offset in Statement of Condition	-45	[2]	-19	[2]
Net Amounts of Liabilities Presented in Statement of Condition	262		326
Foreign exchange contracts	'		'
Offsetting Liabilities [Line Items]	'		'
Gross Amounts of Recognized Liabilities	10,261	[1]	9,084	[1]
Gross Amounts Offset in Statement of Condition	-3,757	[2]	-3,574	[2]
Net Amounts of Liabilities Presented in Statement of Condition	6,504		5,510
Other derivative contracts	'		'
Offsetting Liabilities [Line Items]	'		'
Gross Amounts of Recognized Liabilities	9	[1]	9	[1]
Gross Amounts Offset in Statement of Condition	0	[2]	0	[2]
Net Amounts of Liabilities Presented in Statement of Condition	9		9
Cash collateral netting	'		'
Offsetting Liabilities [Line Items]	'		'
Gross Amounts of Recognized Liabilities	0	[1]	0	[1]
Gross Amounts Offset in Statement of Condition	-468	[2]	-478	[2]
Net Amounts of Liabilities Presented in Statement of Condition	($468)		($478)
[1]	Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.
[2]	Amounts subject to netting arrangements which have been determined to be legally enforceable.
[3]	Included in the $16,514 million as of September 30, 2013 was $10,123 million of repurchase agreements and $6,391 million of collateral related to securities lending. Included in the $12,992 million as of December 31, 2012 was $8,006 million of repurchase agreements and $4,986 million of collateral related to securities lending. Repurchase agreements and collateral related to securities lending were recorded in securities sold under repurchase agreements and accrued expenses and other liabilities, respectively, in our consolidated statement of condition. Refer to note 8 for additional information with respect to principal securities finance transactions.

Offsetting_Arrangements_Liabil1

Offsetting Arrangements (Liabilities With Enforceable Netting Arrangements) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Offsetting [Abstract]	'		'
Derivative, Net Amount of Liabilities Presented in Statement of Condition	$6,307	[1]	$5,367	[1]
Derivative, Counterparty Netting	0	[2]	0	[2]
Derivative, Collateral Provided	0	[2]	0	[2]
Derivative, Net Amount	6,307	[3]	5,367	[3]
Repurchase Agreements and Securities Lending, Net Amount of Liabilities Presented in Statement of Condition	16,514	[4]	12,992	[4]
Repurchase Agreements and Securities Lending, Counterparty Netting	-144	[2]	-126	[2]
Repurchase Agreements and Securities Lending, Collateral Provided	-14,002	[2]	-12,067	[2]
Repurchase Agreements and Securities Lending, Net Amount	2,368	[3]	799	[3]
Total, Net Amount of Liabilities Presented in Statement of Condition	22,821		18,359
Total, Counterparty Netting	-144	[2]	-126	[2]
Total, Collateral Provided	-14,002	[2]	-12,067	[2]
Total, Net Amount	$8,675	[3]	$6,166	[3]
[1]	Amounts include all transactions regardless of whether or not they are subject to an enforceable netting arrangement.
[2]	Amounts subject to netting arrangements which have been determined to be legally enforceable
[3]	Includes amounts secured by collateral not determined to be subject to enforceable netting arrangements.
[4]	Included in the $16,514 million as of September 30, 2013 was $10,123 million of repurchase agreements and $6,391 million of collateral related to securities lending. Included in the $12,992 million as of December 31, 2012 was $8,006 million of repurchase agreements and $4,986 million of collateral related to securities lending. Repurchase agreements and collateral related to securities lending were recorded in securities sold under repurchase agreements and accrued expenses and other liabilities, respectively, in our consolidated statement of condition. Refer to note 8 for additional information with respect to principal securities finance transactions.

Net_Interest_Revenue_Component

Net Interest Revenue (Components of Interest Revenue and Interest Expenses) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Interest Revenue [Abstract]	'	'	'	'
Deposits with banks	$29	$31	$91	$108
U.S. Treasury and federal agencies	165	200	542	605
State and political subdivisions	59	53	164	161
Other investments	323	374	1,003	1,185
Securities purchased under resale agreements	8	15	33	37
Loans and leases	58	57	193	183
Other interest-earning assets	1	0	4	2
Total interest revenue	643	730	2,030	2,281
Deposits	17	37	78	127
Short-term borrowings	15	18	46	55
Long-term debt	59	52	169	172
Other interest-bearing liabilities	6	4	19	11
Total interest expense	97	111	312	365
Net interest revenue	$546	$619	$1,718	$1,916

Acquisition_and_Restructuring_2

Acquisition and Restructuring Costs (Narrative) (Details) (USD $)

3 Months Ended

9 Months Ended

12 Months Ended

45 Months Ended

9 Months Ended

12 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

3 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2011

Dec. 31, 2011

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Business Operations And Information Technology Transformation Program

Business Operations And Information Technology Transformation Program

Business Operations And Information Technology Transformation Program

Business Operations And Information Technology Transformation Program

Business Operations And Information Technology Transformation Program

Business Operations And Information Technology Transformation Program

Business Operations And Information Technology Transformation Program

Business Operations And Information Technology Transformation Program

Expenses Control Measures

Expenses Control Measures

Expenses Control Measures - Additional Targeted Staff Reductions

Expenses Control Measures - Additional Targeted Staff Reductions

Expenses Control Measures - Additional Targeted Staff Reductions

Expenses Control Measures - Additional Targeted Staff Reductions

Expenses Control Measures - Additional Targeted Staff Reductions

Expenses Control Measures - Additional Targeted Staff Reductions

Involuntary Terminations [Member]

Involuntary Terminations [Member]

Involuntary Terminations [Member]

Involuntary Terminations [Member]

Involuntary Terminations [Member]

Involuntary Terminations [Member]

Involuntary Terminations After Replacements [Member]

employee

employee

employee

employee

employee

employee

employee

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restructuring charges, net

$12

$15

$22

$45

$19

$67

$133

$156

$375

'

'

'

$120

'

$1

$3

$133

'

'

'

Expected number of positions eliminated

'

'

'

'

'

'

'

'

'

263

1,234

1,400

'

442

'

'

'

960

'

630

Percent of actual number of positions eliminated

'

'

'

'

'

'

'

'

'

'

'

5.00%

'

'

'

'

'

'

'

'

Number of positions eliminated from inception to date

'

'

'

'

'

'

'

'

'

1,168

'

'

'

'

'

'

'

'

720

'

Acquisition_and_Restructuring_3

Acquisition and Restructuring Costs (Costs Related To Acquisition And Restructuring) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other Expenses [Abstract]	'	'	'	'
Acquisition costs	$18	$13	$52	$41
Restructuring charges, net	12	15	22	45
Total acquisition and restructuring costs	$30	$28	$74	$86

Acquisition_and_Restructuring_4

Acquisition and Restructuring Costs (Activity Related To Restructuring-Related Accruals) (Details) (USD $)	9 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Restructuring Reserve [Roll Forward]	'	'
Balance as of December 31, 2012	$262	'
Additional accruals for Business Operations and Information Technology Transformation program	19	'
Additional accruals for 2012 expense control measures	3	-1
Payments and adjustments	-148	'
Balance as of September 30, 2013	136	262
Employee- Related Costs	'	'
Restructuring Reserve [Roll Forward]	'	'
Balance as of December 31, 2012	195	'
Additional accruals for Business Operations and Information Technology Transformation program	9	'
Additional accruals for 2012 expense control measures	-2	'
Payments and adjustments	-125	'
Balance as of September 30, 2013	77	'
Real Estate Consolidation	'	'
Restructuring Reserve [Roll Forward]	'	'
Balance as of December 31, 2012	49	'
Additional accruals for Business Operations and Information Technology Transformation program	11	'
Additional accruals for 2012 expense control measures	0	'
Payments and adjustments	-11	'
Balance as of September 30, 2013	49	'
Information Technology Costs	'	'
Restructuring Reserve [Roll Forward]	'	'
Balance as of December 31, 2012	5	'
Additional accruals for Business Operations and Information Technology Transformation program	-1	'
Additional accruals for 2012 expense control measures	0	'
Payments and adjustments	-4	'
Balance as of September 30, 2013	0	'
Asset and Other Write-Offs	'	'
Restructuring Reserve [Roll Forward]	'	'
Balance as of December 31, 2012	13	'
Additional accruals for Business Operations and Information Technology Transformation program	0	'
Additional accruals for 2012 expense control measures	5	'
Payments and adjustments	-8	'
Balance as of September 30, 2013	$10	'

Earnings_Per_Common_Share_Comp

Earnings Per Common Share (Computation of Basic and Diluted Earnings Per Share) (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Earnings Per Share [Abstract]	'		'		'		'
Net income	$540		$674		$1,583		$1,591
Less: Preferred stock dividends	-7		-15		-20		-29
Less: Dividends and undistributed earnings allocated to participating securities	-2	[1]	-5	[1]	-6	[1]	-11	[1]
Net income available to common shareholders	$531		$654		$1,557		$1,551
Basic average common shares	442,860		472,355		449,742		479,536
Effect of dilutive securities: common stock options and common stock awards (in shares)	9,294		7,655		8,650		6,277
Diluted average shares	452,154		480,010		458,392		485,813
Anti-dilutive securities (in shares)	1,788	[2]	5,443	[2]	2,384	[2]	5,613	[2]
Earnings per Common Share:	'		'		'		'
Basic (per share)	$1.20		$1.39		$3.46		$3.23
Diluted (per share)	$1.17		$1.36		$3.40		$3.19
[1]	Represented the portion of net income available to common equity allocated to participating securities; participating securities, composed of unvested restricted stock and director stock awards, contain non-forfeitable rights to dividends during the vesting period on a basis equivalent to dividends paid to common shareholders.
[2]	Represented common stock options and other equity-based awards outstanding, but not included in the computation of diluted average shares because their effect was anti-dilutive.

Line_of_Business_Information_D

Line of Business Information (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
			line_of_business
Segment Reporting Information [Line Items]	'	'	'	'
Number of lines of business	'	'	2	'
Acquisition and restructuring costs	$30,000,000	$28,000,000	$74,000,000	$86,000,000
Provision for litigation exposure and other costs	5,000,000	85,000,000	20,000,000	107,000,000
Credit related to recoveries associated with the 2008 Lehman Brothers bankruptcy	0	362,000,000	0	362,000,000
Servicing fees	1,211,000,000	1,100,000,000	3,587,000,000	3,264,000,000
Management fees	276,000,000	251,000,000	816,000,000	733,000,000
Trading services	256,000,000	232,000,000	833,000,000	767,000,000
Securities finance	74,000,000	91,000,000	283,000,000	331,000,000
Processing fees and other	66,000,000	45,000,000	192,000,000	187,000,000
Total fee revenue	1,883,000,000	1,719,000,000	5,711,000,000	5,282,000,000
Net interest revenue	546,000,000	619,000,000	1,718,000,000	1,916,000,000
Gains (losses) related to investment securities, net	-4,000,000	18,000,000	-9,000,000	2,000,000
Total revenue	2,425,000,000	2,356,000,000	7,420,000,000	7,200,000,000
Provision for loan losses	0	0	0	-1,000,000
Total expenses	1,722,000,000	1,415,000,000	5,346,000,000	5,022,000,000
Income before income tax expense	703,000,000	941,000,000	2,074,000,000	2,179,000,000
Pre-tax margin	29.00%	40.00%	28.00%	30.00%
Quarter To Date [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Average assets	201,300,000,000	195,800,000,000	201,300,000,000	195,800,000,000
Year To Date [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Average assets	205,700,000,000	191,000,000,000	205,700,000,000	191,000,000,000
Investment Servicing	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Servicing fees	1,211,000,000	1,100,000,000	3,587,000,000	3,264,000,000
Management fees	0	0	0	0
Trading services	242,000,000	208,000,000	778,000,000	695,000,000
Securities finance	69,000,000	81,000,000	255,000,000	296,000,000
Processing fees and other	60,000,000	38,000,000	181,000,000	183,000,000
Total fee revenue	1,582,000,000	1,427,000,000	4,801,000,000	4,438,000,000
Net interest revenue	527,000,000	600,000,000	1,655,000,000	1,858,000,000
Gains (losses) related to investment securities, net	-4,000,000	18,000,000	-9,000,000	48,000,000
Total revenue	2,105,000,000	2,045,000,000	6,447,000,000	6,344,000,000
Provision for loan losses	'	'	0	-1,000,000
Total expenses	1,496,000,000	1,459,000,000	4,628,000,000	4,537,000,000
Income before income tax expense	609,000,000	586,000,000	1,819,000,000	1,808,000,000
Pre-tax margin	29.00%	29.00%	28.00%	28.00%
Investment Servicing | Quarter To Date [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Average assets	197,700,000,000	192,100,000,000	197,700,000,000	192,100,000,000
Investment Servicing | Year To Date [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Average assets	201,900,000,000	187,200,000,000	201,900,000,000	187,200,000,000
Investment Management	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Servicing fees	0	0	0	0
Management fees	276,000,000	251,000,000	816,000,000	733,000,000
Trading services	14,000,000	24,000,000	55,000,000	72,000,000
Securities finance	5,000,000	10,000,000	28,000,000	35,000,000
Processing fees and other	6,000,000	7,000,000	11,000,000	4,000,000
Total fee revenue	301,000,000	292,000,000	910,000,000	844,000,000
Net interest revenue	19,000,000	19,000,000	63,000,000	58,000,000
Gains (losses) related to investment securities, net	0	0	0	0
Total revenue	320,000,000	311,000,000	973,000,000	902,000,000
Provision for loan losses	'	'	0	0
Total expenses	191,000,000	205,000,000	624,000,000	654,000,000
Income before income tax expense	129,000,000	106,000,000	349,000,000	248,000,000
Pre-tax margin	40.00%	34.00%	36.00%	27.00%
Investment Management | Quarter To Date [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Average assets	3,600,000,000	3,700,000,000	3,600,000,000	3,700,000,000
Investment Management | Year To Date [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Average assets	3,800,000,000	3,800,000,000	3,800,000,000	3,800,000,000
Other	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Servicing fees	0	0	0	0
Management fees	0	0	0	0
Trading services	0	0	0	0
Securities finance	0	0	0	0
Processing fees and other	0	0	0	0
Total fee revenue	0	0	0	0
Net interest revenue	'	'	0	0
Gains (losses) related to investment securities, net	0	0	0	-46,000,000
Total revenue	0	0	0	-46,000,000
Provision for loan losses	'	'	0	0
Total expenses	35,000,000	-249,000,000	94,000,000	-169,000,000
Income before income tax expense	($35,000,000)	$249,000,000	($94,000,000)	$123,000,000

NonUS_Activities_Schedule_Of_R

Non-U.S. Activities (Schedule Of Results From Non-U.S. Operations) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]	'	'	'	'
Total fee revenue	$1,883	$1,719	$5,711	$5,282
Net interest revenue	546	619	1,718	1,916
Gains (losses) related to investment securities, net	-4	18	-9	2
Total revenue	2,425	2,356	7,420	7,200
Expenses	1,722	1,415	5,346	5,022
Income before income tax expense	703	941	2,074	2,179
Income tax expense	163	267	491	588
Net income	540	674	1,583	1,591
Non- U.S. [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total fee revenue	771	700	2,347	2,169
Net interest revenue	306	240	874	709
Gains (losses) related to investment securities, net	-2	-4	-12	-36
Total revenue	1,075	936	3,209	2,842
Expenses	786	708	2,279	2,226
Income before income tax expense	289	228	930	616
Income tax expense	74	57	228	153
Net income	$215	$171	$702	$463

NonUS_Activities_Summary_Of_No

Non-U.S. Activities (Summary Of Non-U.S. Assets) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Segment Reporting Information [Line Items]	'	'
Interest-bearing deposits with banks	$38,636	$50,763
Other assets	23,357	18,016
Total assets	217,180	222,582
Non-U.S. Assets [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest-bearing deposits with banks	5,221	20,665
Investment securities	30,586	28,976
Other assets	16,982	13,441
Total assets	$52,789	$63,082