Summary Of Significant Accounting Policies (Policy)	12 Months Ended
Dec. 31, 2011
Summary Of Significant Accounting Policies [Abstract]
Basis Of Presentation	Basis of Presentation: Our consolidated financial statements include the accounts of the parent company and its majority- and wholly-owned subsidiaries, including State Street Bank. All material inter-company transactions and balances have been eliminated. Certain previously reported amounts have been reclassified to conform to current year presentation. We consolidate subsidiaries in which we hold a majority of the voting rights or exercise control. Investments in unconsolidated subsidiaries, recorded in other assets, generally are accounted for under the equity method of accounting if we have the ability to exercise significant influence over the operations of the investee. For investments accounted for under the equity method, our share of income or loss is recorded in processing fees and other revenue in our consolidated statement of income. Investments not meeting the criteria for equity method treatment are accounted for under the cost method of accounting.
Foreign Currency Translation	Foreign Currency Translation: The assets and liabilities of our operations with functional currencies other than the U.S. dollar are translated at month- end exchange rates, and revenues and expenses are translated at rates that approximate average monthly exchange rates. Gains or losses from the translation of the net assets of subsidiaries with functional currencies other than the U.S. dollar, net of related taxes, are recorded in accumulated other comprehensive income, a component of shareholders' equity.
Cash And Cash Equivalents	Cash and Cash Equivalents: For purposes of the consolidated statement of cash flows, cash and cash equivalents are defined as cash and due from banks.
Interest-Bearing Deposits With Banks	Interest-bearing Deposits with Banks: Interest-bearing deposits with banks generally consist of highly liquid, short-term investments maintained at the Federal Reserve Bank and other central banks with original maturities at the time of purchase of one month or less.
Securities Purchased Under Resale Agreements And Securities Sold Under Repurchase Agreements	Securities Purchased Under Resale Agreements and Securities Sold Under Repurchase Agreements: U.S. Treasury and federal agency securities, referred to as "U.S. government securities," purchased under resale agreements or sold under repurchase agreements are treated as collateralized financing transactions, and are recorded in our consolidated statement of condition at the amounts at which the securities will be subsequently resold or repurchased, plus accrued interest. Our policy is to take possession or control of securities underlying resale agreements, allowing borrowers the right of collateral substitution and/or short-notice termination. We revalue these securities daily to determine if additional collateral is necessary from the borrower to protect us against credit exposure. We can use these securities as collateral for repurchase agreements. For securities sold under repurchase agreements collateralized by our U.S. government securities portfolio, the dollar value of the U.S. government securities remains in investment securities in our consolidated statement of condition. Where a master netting agreement exists or both parties are members of a common clearing organization, resale and repurchase agreements with the same counterparty or clearing house and maturity date are reported on a net basis.
Investment Securities	Investment Securities: Investment securities held by us are classified as either trading account assets, investment securities available for sale or investment securities held to maturity at the time of purchase, based on management's intent. Trading account assets are debt and equity securities purchased in connection with our trading activities and, as such, are expected to be sold in the near term. Our trading activities typically involve active and frequent buying and selling with the objective of generating profits on short-term movements. Securities available for sale are those that we intend to hold for an indefinite period of time. Available-for-sale securities include securities utilized as part of our asset and liability management activities that may be sold in response to changes in interest rates, prepayment risk, liquidity needs or other factors. Securities held to maturity are debt securities that management has the intent and the ability to hold to maturity. Trading account assets are carried at fair value. Both realized and unrealized gains and losses on trading account assets are recorded in trading services revenue in our consolidated statement of income. Debt and marketable equity securities classified as available for sale are carried at fair value, and after-tax net unrealized gains and losses are recorded in accumulated other comprehensive income. Gains or losses realized on sales of available-for-sale securities are computed using the specific identification method and are recorded in gains related to investment securities, net, in our consolidated statement of income. Securities held to maturity are carried at cost, adjusted for amortization of premiums and accretion of discounts. We review the fair values of debt securities at least quarterly, and evaluate individual securities for impairment that may be deemed to be other than temporary. For impaired securities that we plan to sell, or when it is more likely than not that we will be forced to sell the security, the impairment is deemed to be other than temporary and the security is written down to its fair value. Otherwise, we determine whether or not we expect to recover the entire amortized cost basis of the security, primarily by comparing the present value of expected future principal, interest and other contractual cash flows to the security's amortized cost basis. Our evaluation of impairment of mortgage- and asset-backed securities incorporates detailed information with respect to underlying loan-level performance. Accordingly, the range of estimates pertaining to each collateral type reflects the unique characteristics of the underlying loans, such as payment options and collateral geography, among other factors. When we conclude that other-than-temporary impairment exists and we have no intention to sell, or will not be forced to sell, the security, the impairment is separated into the amount related to credit losses and the amount related to factors other than credit. The amount related to credit losses is recognized in our consolidated statement of income in gains (losses) related to investment securities, net, and the amortized cost basis of the security is written down by this amount. The portion of impairment related to all other factors is recognized in other comprehensive income. Interest revenue related to debt securities is recognized in our consolidated statement of income using the interest method, or on a basis approximating a level rate of return over the contractual or estimated life of the security. The level rate of return considers any nonrefundable fees or costs, as well as purchase premiums or discounts, resulting in amortization or accretion, accordingly. With respect to debt securities acquired, for those which we consider it probable as of the date of acquisition that we will be unable to collect all contractually required principal, interest and other payments, the excess of our estimate of undiscounted future cash flows from these securities over their initial recorded investment is accreted into interest revenue on a level-yield basis over the securities' estimated remaining terms. Subsequent decreases in these securities' expected future cash flows are either recognized prospectively through an adjustment of the yields on the securities over their remaining terms, or are evaluated for other-than-temporary impairment as described above. Increases in expected future cash flows are recognized prospectively over the securities' estimated remaining terms through the recalculation of their yields. With respect to certain debt securities acquired which are considered to be beneficial interests in securitized financial assets, the excess of our estimate of undiscounted future cash flows from these securities over their initial recorded investment is accreted into interest revenue on a level-yield basis over the securities' estimated remaining terms. Subsequent decreases in these securities' expected future cash flows are either recognized prospectively through an adjustment of the yields on the securities over their remaining terms, or are evaluated for other-than-temporary impairment as described above. Increases in expected future cash flows are recognized prospectively over the securities' estimated remaining terms through the recalculation of their yields.
Loans And Leases	Loans and Leases: Loans generally are recorded at their principal amount outstanding, net of the allowance for loan losses, unearned income, and any net unamortized deferred loan origination fees. Acquired loans are recorded at fair value, based on management's expectation with respect to future principal and interest collection as of the date of acquisition. Loans acquired with evidence of deterioration in credit quality subsequent to origination, and for which our inability to collect all contractually required payments is probable on the date of acquisition, are recorded at fair value. The excess of expected future cash flows from these loans over their initial recorded investment is accreted into interest revenue on a level- yield basis over the remaining life of the loans. The carrying amount of acquired loans is assessed on an ongoing basis using a discounted cash flow model, which incorporates management expectations of prepayments. Subsequent decreases in expected cash flows result in an addition to the related allowance to allow the loan to maintain its level yield. Increases in expected cash flows are recognized, first, as a reduction of any remaining allowance, and then are recognized prospectively over the remaining life of the loan through a recalculation of the loan's level yield. Interest revenue related to loans is recognized in our consolidated statement of income using the interest method or on a basis approximating a level rate of return over the term of the loan. Fees received for providing loan commitments and letters of credit that we anticipate will result in loans typically are deferred and amortized to interest revenue over the life of the related loan, beginning with the initial borrowing. Fees on commitments and letters of credit are amortized to processing fees and other revenue over the commitment period when funding is not known or expected. For all loan classes, other than loans acquired with evidence of deterioration in credit quality, loans are placed on non- accrual status when they become 60 days past-due as to either principal or interest, or earlier when full collection of principal or interest is not considered probable. Loans 60 days past-due, but considered both well secured and in the process of collection, are treated as exceptions and may be excluded from non-accrual status. When we place a loan on non-accrual status, the accrual of interest is discontinued and previously recorded but unpaid interest is reversed and generally charged against interest revenue. For loans on non-accrual status, revenue is recognized on a cash basis after recovery of principal, if and when interest payments are received. Loans may be removed from non-accrual status when repayment is reasonably assured and performance under the terms of the loan has been demonstrated. In certain circumstances, we restructure troubled loans by granting concessions to borrowers experiencing financial difficulty. Once restructured, the loans are generally considered impaired until their maturity, regardless of whether the borrowers perform under the modified terms of the loans. Leveraged lease investments are reported at the aggregate of lease payments receivable and estimated residual values, net of non-recourse debt and unearned income. Lease residual values are reviewed regularly for other-than-temporary impairment, with valuation adjustments recorded currently against processing fees and other revenue. Unearned income is recognized to yield a level rate of return on the net investment in the leases. Gains and losses on residual values of leased equipment sold are recorded in processing fees and other revenue.
Allowance For Loan Losses	Allowance for Loan Losses: The allowance for loan losses, recorded as a reduction of loans and leases in our consolidated statement of condition, represents management's estimate of probable credit losses inherent in our loan and lease portfolio as of the balance sheet date. The allowance is evaluated on a regular basis by management. Factors considered in evaluating the appropriate level of the allowance for both the institutional and commercial real estate segments of our loan and lease portfolio include previous loss experience, current economic conditions and adverse situations that may affect the borrower's ability to repay, the estimated value of the underlying collateral, if any, the performance of individual credits in relation to contract terms, and other relevant factors. Provisions for loan losses reflect our estimate of the amount necessary to maintain the allowance at a level considered by us to be appropriate to absorb estimated probable credit losses inherent in the loan and lease portfolio. Loans are charged off to the allowance for loan losses in the reporting period in which either an event occurs that confirms the existence of a loss on a loan or a portion of a loan is determined to be uncollectible. In addition, any impaired loan that is determined to be collateral dependent is reduced to an amount equal to the fair value of the collateral less costs to sell. A loan is identified as collateral dependent when management determines that it is probable that the underlying collateral will be the sole source of repayment. Recoveries are recorded as adjustments to the allowance on a cash basis. In addition, we maintain a reserve for off-balance sheet credit exposures that is recorded in other liabilities in our consolidated statement of condition. Factors considered in evaluating the appropriate level of this reserve are similar to those considered with respect to the allowance for loan losses. Provisions to change the level of this reserve are recorded in other expenses in our consolidated statement of income.
Premises And Equipment	Premises and Equipment: Buildings, leasehold improvements, computers, software and other equipment are carried at cost less accumulated depreciation and amortization. Depreciation and amortization, recorded in occupancy expense and information systems and communications expense in our consolidated statement of income, are computed using the straight-line method over the estimated useful lives of the related assets or the remaining terms of the leases, generally three to forty years. Maintenance and repairs are charged to expense as incurred, while major leasehold improvements are capitalized and expensed over their estimated useful lives or the remaining terms of the lease. For premises held under leases for which we have an obligation to restore the facilities to their original condition upon expiration of the lease, we expense the anticipated related costs over the term of the lease. Costs related to internal-use software development projects that provide significant new functionality are capitalized. We consider projects for capitalization that are expected to yield long-term operational benefits, such as applications that result in operational efficiencies and/or incremental revenue streams.
Goodwill And Other Intangible Assets	Goodwill and Other Intangible Assets: Goodwill represents the excess of the cost of an acquisition over the fair value of the net tangible and other intangible assets acquired. Other intangible assets represent purchased assets that can be distinguished from goodwill because of contractual rights or because the asset can be exchanged on its own or in combination with a related contract, asset or liability. Goodwill is not amortized, but is subject to annual evaluation for impairment. Other intangible assets related to customer relationships generally are amortized on a straight-line basis over periods ranging from five to twenty years, and core deposit intangible assets over periods ranging from sixteen to twenty-two years, with amortization recorded in other expenses. Impairment of goodwill is deemed to exist if the carrying value of a reporting unit, including its allocation of goodwill and other intangible assets, exceeds its estimated fair value. Impairment of other intangible assets is deemed to exist if the balance of the other intangible asset exceeds the cumulative expected net cash inflows related to the asset over its remaining estimated useful life. If these reviews determine that goodwill or other intangible assets are impaired, the value of the goodwill or the other intangible asset is written down through a charge to other expenses.
Fee And Net Interest Revenue	Fee and Net Interest Revenue: Fees from investment servicing, investment management, securities finance, trading services and certain types of processing fees and other revenue are recorded in our consolidated statement of income based on estimates or specific contractual terms as transactions occur or services are rendered, provided that persuasive evidence exists, the price to the client is fixed or determinable and collectability is reasonably assured. Amounts accrued at period-end are recorded in accrued income receivable in our consolidated statement of condition. Performance fees from investment management are recorded when earned, based on predetermined benchmarks associated with the applicable fund's performance. Interest revenue on interest-earning assets and interest expense on interest-bearing liabilities are recorded in our consolidated statement of income as components of net interest revenue, and are generally based on the effective yield of the related financial asset or liability.
Employee Benefits Expense	Employee Benefits Expense: Employee benefits expense, recorded in our consolidated statement of income, includes costs of certain pension and other post-retirement benefit plans related to prior and current service, which are accrued on a current basis, as well as contributions associated with defined contribution savings plans, unrestricted cash and stock awards under other employee incentive compensation plans, and the amortization of restricted stock awards.
Equity-Based Compensation	Equity-Based Compensation: We record compensation expense for equity-based awards. Accordingly, we measure compensation expense at fair value on a straight-line basis over the service or performance period, net of estimated forfeitures. The fair values of equity-based awards, such as restricted stock, deferred stock and performance awards, are based on the closing price of our common stock on the date of grant, adjusted if appropriate based upon the award's eligibility to receive dividends. The fair value of stock options and stock appreciation rights is determined using the Black-Scholes valuation model. Compensation expense related to equity-based awards with service-only conditions and terms that provide for a graded vesting schedule are recognized on a straight-line basis over the required service period for the entire award. Compensation expense related to equity-based awards with performance conditions and terms that provide for a graded vesting schedule is recognized over the requisite service period for each separately vesting tranche of the award, and is based on the probable outcome of the performance conditions at each reporting date. The expense is adjusted for assumptions with respect to the estimated amount of awards that will be forfeited prior to vesting, and for employees who have met certain retirement eligibility criteria. Dividend equivalents for certain equity-based awards are paid on stock units on a current basis prior to vesting and distribution. Compensation expense for common stock and cash awards granted to employees meeting early retirement eligibility criteria is fully expensed and accrued at the grant date.
Income Taxes	Income Taxes: We use an asset and liability approach to account for income taxes. Our objective is to recognize the amount of taxes payable or refundable for the current year through charges or credits to the current tax provision, and to recognize deferred tax assets and liabilities for the future tax consequences resulting from temporary differences between the amounts reported in our consolidated financial statements and their respective tax bases. The measurement of tax assets and liabilities is based on enacted tax laws and applicable tax rates. The effects of a tax position on our consolidated financial statements are recognized when we believe it more likely than not that the position will be sustained. A deferred tax valuation allowance is established if it is considered more likely than not that all or a portion of the deferred tax assets will not be realized. Deferred tax assets and liabilities are netted within the same tax jurisdiction.
Earnings Per Share	Earnings Per Share: Basic earnings per share, or EPS, is calculated pursuant to the "two-class" method, using net income available to common shareholders and the weighted-average number of common shares outstanding during the period. Diluted EPS is calculated pursuant to the two-class method, by dividing net income available to common shareholders by the weighted-average number of common shares outstanding for the period and the shares representing the dilutive effect of common stock options and other equity-based awards. The effect of common stock options and other equity-based awards is excluded from the calculation of diluted EPS in periods in which their effect would be anti-dilutive. The two-class method requires the allocation of undistributed net income between common and participating shareholders. Net income available to common shareholders, presented separately in our consolidated statement of income, is the basis for the calculation of both basic and diluted EPS. Participating securities are composed of unvested restricted stock and director stock awards, which are equity-based awards that contain non-forfeitable rights to dividends, and are considered to participate with common shareholders in undistributed earnings.
Fair Value Measurements	Fair Value Measurements: We carry certain of our financial assets and liabilities at fair value on a recurring basis. These financial assets and liabilities are composed of trading account assets, investment securities available for sale and various types of derivative financial instruments. In addition, we measure certain assets, such as goodwill, investment securities held to maturity and other long-lived assets, at fair value on a non-recurring basis to evaluate those assets for potential impairment. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. We categorize our financial assets and liabilities into the following fair value hierarchy: Level 1 – Financial assets and liabilities with values based on unadjusted quoted prices for identical assets or liabilities in an active market. Examples of level 1 financial instruments include active exchange-traded equity securities and certain U.S. government 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. Examples of level 2 financial instruments include various types of fixed-income investment securities and interest-rate and foreign exchange derivative instruments. Pricing models are utilized to estimate fair value for certain financial assets and liabilities categorized in level 2. 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 fair value measurement. These inputs reflect management's judgment about the assumptions that a market participant would use in pricing the asset or liability, and are based on the best available information, some of which is internally developed. Examples of level 3 financial instruments include certain asset- and mortgage-backed securities and certain derivative instruments with little or no market activity and a resulting lack of price transparency. When determining the fair value measurements for financial assets and liabilities carried at fair value on a recurring basis, we consider the principal or most advantageous market in which we would transact and consider assumptions that market participants would use when pricing the asset or liability. When possible, we look to active and observable markets to price identical assets or liabilities. When identical assets and liabilities are not traded in active markets, we look to market observable data for similar assets and liabilities. Nevertheless, certain assets and liabilities are not actively traded in observable markets, and we use alternative valuation techniques to derive fair value measurements.
Variable Interest Entities	Variable Interest Entities: We are involved in the normal course of our business with various types of special purpose entities, some of which are variable interest entities, or VIEs, as defined by GAAP. We also 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 entities are considered to be VIEs. 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. We use special purpose entities to structure and sell certificated interests in pools of tax-exempt investment-grade assets, principally to our mutual fund clients. These trusts are recorded in our consolidated financial statements. We transfer assets to these trusts, which are legally isolated from us, from our investment securities portfolio at adjusted book value. 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. The investment securities of the trusts are carried at fair value in investment securities available for sale. The certificated interests are carried at the amount owed to the third-party investors in other short-term borrowings. The interest revenue and interest expense generated by the investments and certificated interests, respectively, are recorded as components of net interest revenue when earned or incurred.
Derivative Financial Instruments	Derivative Financial Instruments: A derivative financial instrument is a financial instrument or other contract which has one or more referenced indices and one or more notional amounts, either no initial net investment or a smaller initial net investment than would be expected for similar types of contracts, and which requires or permits net settlement. Derivatives that we enter into include forwards, futures, swaps, options and other instruments with similar characteristics. We record derivatives in our consolidated statement of condition at their fair value. On the date a derivative contract is entered into, we designate the derivative as: (1) a hedge of the fair value of a recognized fixed-rate asset or liability or of an unrecognized firm commitment (a "fair value" hedge); (2) a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized variable-rate asset or liability (a "cash flow" hedge); (3) a foreign currency fair value or cash flow hedge (a "foreign currency" hedge); (4) a hedge of a net investment in a non-U.S. operation; or (5) a derivative utilized in either our trading activities or in our asset and liability management activities that is not accounted for as a hedge of an asset or liability. Changes in the fair value of a derivative that is highly effective—and that is designated and qualifies as a fair value hedge—are recorded currently in processing fees and other revenue, along with the changes in fair value of the hedged asset or liability attributable to the hedged risk. Changes in the fair value of a derivative that is highly effective—and that is designated and qualifies as a cash flow hedge—are recorded, net of tax, in other comprehensive income, until earnings are affected by the hedged cash flows (e.g., when periodic settlements on a variable-rate asset or liability are recorded in earnings). Ineffectiveness of cash flow hedges, defined as the extent to which the changes in fair value of the derivative exceed the variability of cash flows of the forecasted transaction, is recorded in processing fees and other revenue. Changes in the fair value of a derivative that is highly effective—and that is designated and qualifies as a foreign currency hedge—are recorded currently either in processing fees and other revenue or in other comprehensive income, net of tax, depending on whether the hedge transaction meets the criteria for a fair value or a cash flow hedge. If, however, a derivative is used as a hedge of a net investment in a non-U.S. operation, its changes in fair value, to the extent effective as a hedge, are recorded, net of tax, in the foreign currency translation component of other comprehensive income. Lastly, entire changes in the fair value of derivatives utilized in our trading activities are recorded in trading services revenue, and entire changes in the fair value of derivatives utilized in our asset and liability management activities are recorded in processing fees and other revenue. At both the inception of the hedge and on an ongoing basis, we formally assess and document the effectiveness of a derivative designated as a hedge in offsetting changes in the fair value of hedged items and the likelihood that the derivative will be an effective hedge in future periods. We discontinue hedge accounting prospectively when we determine that the derivative is no longer highly effective in offsetting changes in fair value or cash flows of the underlying risk being hedged, the derivative expires, terminates or is sold, or management discontinues the hedge designation. Unrealized gains and losses on foreign exchange and interest-rate contracts are reported at fair value in our consolidated statement of condition as a component of other assets and other liabilities, respectively, on a gross basis, except where such gains and losses arise from contracts covered by qualifying master netting agreements.
Recent Accounting Developments	Recent Accounting Developments: The FASB is currently deliberating potentially significant changes to the U.S. accounting framework as part of an overall convergence effort with the International Accounting Standards Board under a previously signed memorandum of understanding. Some of these proposed changes have been exposed for comment, while others are expected to be exposed for comment over the next six to twelve months. These new proposals include potential changes to the accounting for financial instruments and hedging, the accounting for leases, revenue recognition and financial statement presentation. Once these proposed changes are finalized, we will disclose their nature and potential effect, if any, on our consolidated financial statements in our future filings. These proposed changes may have a material effect on our consolidated financial statements. In September 2011, the FASB issued an amendment to GAAP that modifies existing guidance with respect to impairment of goodwill. The amendment provides companies with an option to perform a qualitative assessment to determine whether further impairment testing is necessary. The amendment is effective, for State Street, for interim and annual periods beginning on January 1, 2012. Adoption of the amendment is not expected to have a material effect on our consolidated financial statements. In June 2011, the FASB issued an amendment to GAAP that eliminates the option to report other comprehensive income and its components in the statement of changes in shareholders' equity. Instead, an entity can elect to present the components of net income and other comprehensive income in either one continuous statement, referred to as the statement of comprehensive income, or in two separate, but consecutive statements. The amendment does not change which items are reported in other comprehensive income or the requirement to report reclassifications of items from other comprehensive income to net income. The amendment is effective, for State Street, for interim and annual periods beginning on January 1, 2012, and is required to be applied retrospectively. We are currently evaluating the options for presentation of other comprehensive income permitted by the amendment. In May 2011, the FASB issued an amendment to GAAP associated with fair value measurement and related disclosures. While the amendment is not expected to significantly affect current practice, it clarifies the FASB's intent about the application of existing fair value measurement requirements, and requires the disclosure of additional quantitative information about fair value measurements. The amendment includes guidance about, among other things, the determination of a principal market and the measurement of fair value of instruments with offsetting market or counterparty credit risks. The amendment is effective, for State Street, for interim and annual periods beginning on January 1, 2012, and is required to be applied prospectively. Adoption of the amendment is not expected to have a material effect on our consolidated financial statements from a fair value measurement perspective. However, adoption is expected to result in additional disclosures in our consolidated financial statements. In April 2011, the FASB issued an amendment to GAAP that eliminates the requirement to consider collateral maintenance when determining whether a transfer of assets subject to a repurchase arrangement is accounted for as a sale or as a secured borrowing. The amendment is effective prospectively, for State Street, for new transactions and modifications of existing transactions that occur on or after January 1, 2012. Adoption of the amendment is not expected to have a material effect on our consolidated financial statements, since we currently account for repurchase agreements as secured borrowings.

Summary Of Significant Accounting Policies (Policy)

12 Months Ended

Dec. 31, 2011

Summary Of Significant Accounting Policies [Abstract]

Basis of Presentation:

Our consolidated financial statements include the accounts of the parent company and its majority- and wholly-owned subsidiaries, including State Street Bank. All material inter-company transactions and balances have been eliminated. Certain previously reported amounts have been reclassified to conform to current year presentation.

We consolidate subsidiaries in which we hold a majority of the voting rights or exercise control. Investments in unconsolidated subsidiaries, recorded in other assets, generally are accounted for under the equity method of accounting if we have the ability to exercise significant influence over the operations of the investee. For investments accounted for under the equity method, our share of income or loss is recorded in processing fees and other revenue in our consolidated statement of income. Investments not meeting the criteria for equity method treatment are accounted for under the cost method of accounting.

Foreign Currency Translation

Foreign Currency Translation:

The assets and liabilities of our operations with functional currencies other than the U.S. dollar are translated at month- end exchange rates, and revenues and expenses are translated at rates that approximate average monthly exchange rates. Gains or losses from the translation of the net assets of subsidiaries with functional currencies other than the U.S. dollar, net of related taxes, are recorded in accumulated other comprehensive income, a component of shareholders' equity.

Cash And Cash Equivalents

Cash and Cash Equivalents:

For purposes of the consolidated statement of cash flows, cash and cash equivalents are defined as cash and due from banks.

Interest-Bearing Deposits With Banks

Interest-bearing Deposits with Banks:

Interest-bearing deposits with banks generally consist of highly liquid, short-term investments maintained at the Federal Reserve Bank and other central banks with original maturities at the time of purchase of one month or less.

Securities Purchased Under Resale Agreements And Securities Sold Under Repurchase Agreements

Securities Purchased Under Resale Agreements and Securities Sold Under Repurchase Agreements:

U.S. Treasury and federal agency securities, referred to as "U.S. government securities," purchased under resale agreements or sold under repurchase agreements are treated as collateralized financing transactions, and are recorded in our consolidated statement of condition at the amounts at which the securities will be subsequently resold or repurchased, plus accrued interest. Our policy is to take possession or control of securities underlying resale agreements, allowing borrowers the right of collateral substitution and/or short-notice termination. We revalue these securities daily to determine if additional collateral is necessary from the borrower to protect us against credit exposure. We can use these securities as collateral for repurchase agreements. For securities sold under repurchase agreements collateralized by our U.S. government securities portfolio, the dollar value of the U.S. government securities remains in investment securities in our consolidated statement of condition. Where a master netting agreement exists or both parties are members of a common clearing organization, resale and repurchase agreements with the same counterparty or clearing house and maturity date are reported on a net basis.

Investment Securities

Investment Securities:

Investment securities held by us are classified as either trading account assets, investment securities available for sale or investment securities held to maturity at the time of purchase, based on management's intent.

Trading account assets are debt and equity securities purchased in connection with our trading activities and, as such, are expected to be sold in the near term. Our trading activities typically involve active and frequent buying and selling with the objective of generating profits on short-term movements. Securities available for sale are those that we intend to hold for an indefinite period of time. Available-for-sale securities include securities utilized as part of our asset and liability management activities that may be sold in response to changes in interest rates, prepayment risk, liquidity needs or other factors. Securities held to maturity are debt securities that management has the intent and the ability to hold to maturity.

Trading account assets are carried at fair value. Both realized and unrealized gains and losses on trading account assets are recorded in trading services revenue in our consolidated statement of income. Debt and marketable equity securities classified as available for sale are carried at fair value, and after-tax net unrealized gains and losses are recorded in accumulated other comprehensive income. Gains or losses realized on sales of available-for-sale securities are computed using the specific identification method and are recorded in gains related to investment securities, net, in our consolidated statement of income. Securities held to maturity are carried at cost, adjusted for amortization of premiums and accretion of discounts.

We review the fair values of debt securities at least quarterly, and evaluate individual securities for impairment that may be deemed to be other than temporary. For impaired securities that we plan to sell, or when it is more likely than not that we will be forced to sell the security, the impairment is deemed to be other than temporary and the security is written down to its fair value. Otherwise, we determine whether or not we expect to recover the entire amortized cost basis of the security, primarily by comparing the present value of expected future principal, interest and other contractual cash flows to the security's amortized cost basis. Our evaluation of impairment of mortgage- and asset-backed securities incorporates detailed information with respect to underlying loan-level performance. Accordingly, the range of estimates pertaining to each collateral type reflects the unique characteristics of the underlying loans, such as payment options and collateral geography, among other factors.

When we conclude that other-than-temporary impairment exists and we have no intention to sell, or will not be forced to sell, the security, the impairment is separated into the amount related to credit losses and the amount related to factors other than credit. The amount related to credit losses is recognized in our consolidated statement of income in gains (losses) related to investment securities, net, and the amortized cost basis of the security is written down by this amount. The portion of impairment related to all other factors is recognized in other comprehensive income.

Interest revenue related to debt securities is recognized in our consolidated statement of income using the interest method, or on a basis approximating a level rate of return over the contractual or estimated life of the security. The level rate of return considers any nonrefundable fees or costs, as well as purchase premiums or discounts, resulting in amortization or accretion, accordingly.

With respect to debt securities acquired, for those which we consider it probable as of the date of acquisition that we will be unable to collect all contractually required principal, interest and other payments, the excess of our estimate of undiscounted future cash flows from these securities over their initial recorded investment is accreted into interest revenue on a level-yield basis over the securities' estimated remaining terms. Subsequent decreases in these securities' expected future cash flows are either recognized prospectively through an adjustment of the yields on the securities over their remaining terms, or are evaluated for other-than-temporary impairment as described above. Increases in expected future cash flows are recognized prospectively over the securities' estimated remaining terms through the recalculation of their yields.

With respect to certain debt securities acquired which are considered to be beneficial interests in securitized financial assets, the excess of our estimate of undiscounted future cash flows from these securities over their initial recorded investment is accreted into interest revenue on a level-yield basis over the securities' estimated remaining terms. Subsequent decreases in these securities' expected future cash flows are either recognized prospectively through an adjustment of the yields on the securities over their remaining terms, or are evaluated for other-than-temporary impairment as described above. Increases in expected future cash flows are recognized prospectively over the securities' estimated remaining terms through the recalculation of their yields.

Loans And Leases

Loans and Leases:

Loans generally are recorded at their principal amount outstanding, net of the allowance for loan losses, unearned income, and any net unamortized deferred loan origination fees. Acquired loans are recorded at fair value, based on management's expectation with respect to future principal and interest collection as of the date of acquisition.

Loans acquired with evidence of deterioration in credit quality subsequent to origination, and for which our inability to collect all contractually required payments is probable on the date of acquisition, are recorded at fair value. The excess of expected future cash flows from these loans over their initial recorded investment is accreted into interest revenue on a level- yield basis over the remaining life of the loans. The carrying amount of acquired loans is assessed on an ongoing basis using a discounted cash flow model, which incorporates management expectations of prepayments. Subsequent decreases in expected cash flows result in an addition to the related allowance to allow the loan to maintain its level yield. Increases in expected cash flows are recognized, first, as a reduction of any remaining allowance, and then are recognized prospectively over the remaining life of the loan through a recalculation of the loan's level yield.

Interest revenue related to loans is recognized in our consolidated statement of income using the interest method or on a basis approximating a level rate of return over the term of the loan. Fees received for providing loan commitments and letters of credit that we anticipate will result in loans typically are deferred and amortized to interest revenue over the life of the related loan, beginning with the initial borrowing. Fees on commitments and letters of credit are amortized to processing fees and other revenue over the commitment period when funding is not known or expected.

For all loan classes, other than loans acquired with evidence of deterioration in credit quality, loans are placed on non- accrual status when they become 60 days past-due as to either principal or interest, or earlier when full collection of principal or interest is not considered probable. Loans 60 days past-due, but considered both well secured and in the process of collection, are treated as exceptions and may be excluded from non-accrual status. When we place a loan on non-accrual status, the accrual of interest is discontinued and previously recorded but unpaid interest is reversed and generally charged against interest revenue. For loans on non-accrual status, revenue is recognized on a cash basis after recovery of principal, if and when interest payments are received. Loans may be removed from non-accrual status when repayment is reasonably assured and performance under the terms of the loan has been demonstrated.

In certain circumstances, we restructure troubled loans by granting concessions to borrowers experiencing financial difficulty. Once restructured, the loans are generally considered impaired until their maturity, regardless of whether the borrowers perform under the modified terms of the loans.

Leveraged lease investments are reported at the aggregate of lease payments receivable and estimated residual values, net of non-recourse debt and unearned income. Lease residual values are reviewed regularly for other-than-temporary impairment, with valuation adjustments recorded currently against processing fees and other revenue. Unearned income is recognized to yield a level rate of return on the net investment in the leases. Gains and losses on residual values of leased equipment sold are recorded in processing fees and other revenue.

Allowance For Loan Losses

Allowance for Loan Losses:

The allowance for loan losses, recorded as a reduction of loans and leases in our consolidated statement of condition, represents management's estimate of probable credit losses inherent in our loan and lease portfolio as of the balance sheet date. The allowance is evaluated on a regular basis by management. Factors considered in evaluating the appropriate level of the allowance for both the institutional and commercial real estate segments of our loan and lease portfolio include previous loss experience, current economic conditions and adverse situations that may affect the borrower's ability to repay, the estimated value of the underlying collateral, if any, the performance of individual credits in relation to contract terms, and other relevant factors. Provisions for loan losses reflect our estimate of the amount necessary to maintain the allowance at a level considered by us to be appropriate to absorb estimated probable credit losses inherent in the loan and lease portfolio.

Loans are charged off to the allowance for loan losses in the reporting period in which either an event occurs that confirms the existence of a loss on a loan or a portion of a loan is determined to be uncollectible. In addition, any impaired loan that is determined to be collateral dependent is reduced to an amount equal to the fair value of the collateral less costs to sell. A loan is identified as collateral dependent when management determines that it is probable that the underlying collateral will be the sole source of repayment. Recoveries are recorded as adjustments to the allowance on a cash basis.

In addition, we maintain a reserve for off-balance sheet credit exposures that is recorded in other liabilities in our consolidated statement of condition. Factors considered in evaluating the appropriate level of this reserve are similar to those considered with respect to the allowance for loan losses. Provisions to change the level of this reserve are recorded in other expenses in our consolidated statement of income.

Premises And Equipment

Premises and Equipment:

Buildings, leasehold improvements, computers, software and other equipment are carried at cost less accumulated depreciation and amortization. Depreciation and amortization, recorded in occupancy expense and information systems and communications expense in our consolidated statement of income, are computed using the straight-line method over the estimated useful lives of the related assets or the remaining terms of the leases, generally three to forty years. Maintenance and repairs are charged to expense as incurred, while major leasehold improvements are capitalized and expensed over their estimated useful lives or the remaining terms of the lease.

For premises held under leases for which we have an obligation to restore the facilities to their original condition upon expiration of the lease, we expense the anticipated related costs over the term of the lease.

Costs related to internal-use software development projects that provide significant new functionality are capitalized. We consider projects for capitalization that are expected to yield long-term operational benefits, such as applications that result in operational efficiencies and/or incremental revenue streams.

Goodwill And Other Intangible Assets

Goodwill and Other Intangible Assets:

Goodwill represents the excess of the cost of an acquisition over the fair value of the net tangible and other intangible assets acquired. Other intangible assets represent purchased assets that can be distinguished from goodwill because of contractual rights or because the asset can be exchanged on its own or in combination with a related contract, asset or liability. Goodwill is not amortized, but is subject to annual evaluation for impairment. Other intangible assets related to customer relationships generally are amortized on a straight-line basis over periods ranging from five to twenty years, and core deposit intangible assets over periods ranging from sixteen to twenty-two years, with amortization recorded in other expenses.

Impairment of goodwill is deemed to exist if the carrying value of a reporting unit, including its allocation of goodwill and other intangible assets, exceeds its estimated fair value. Impairment of other intangible assets is deemed to exist if the balance of the other intangible asset exceeds the cumulative expected net cash inflows related to the asset over its remaining estimated useful life. If these reviews determine that goodwill or other intangible assets are impaired, the value of the goodwill or the other intangible asset is written down through a charge to other expenses.

Fee And Net Interest Revenue

Fee and Net Interest Revenue:

Fees from investment servicing, investment management, securities finance, trading services and certain types of processing fees and other revenue are recorded in our consolidated statement of income based on estimates or specific contractual terms as transactions occur or services are rendered, provided that persuasive evidence exists, the price to the client is fixed or determinable and collectability is reasonably assured. Amounts accrued at period-end are recorded in accrued income receivable in our consolidated statement of condition. Performance fees from investment management are recorded when earned, based on predetermined benchmarks associated with the applicable fund's performance.

Interest revenue on interest-earning assets and interest expense on interest-bearing liabilities are recorded in our consolidated statement of income as components of net interest revenue, and are generally based on the effective yield of the related financial asset or liability.

Employee Benefits Expense

Employee Benefits Expense:

Employee benefits expense, recorded in our consolidated statement of income, includes costs of certain pension and other post-retirement benefit plans related to prior and current service, which are accrued on a current basis, as well as contributions associated with defined contribution savings plans, unrestricted cash and stock awards under other employee incentive compensation plans, and the amortization of restricted stock awards.

Equity-Based Compensation

Equity-Based Compensation:

We record compensation expense for equity-based awards. Accordingly, we measure compensation expense at fair value on a straight-line basis over the service or performance period, net of estimated forfeitures.

The fair values of equity-based awards, such as restricted stock, deferred stock and performance awards, are based on the closing price of our common stock on the date of grant, adjusted if appropriate based upon the award's eligibility to receive dividends. The fair value of stock options and stock appreciation rights is determined using the Black-Scholes valuation model.

Compensation expense related to equity-based awards with service-only conditions and terms that provide for a graded vesting schedule are recognized on a straight-line basis over the required service period for the entire award. Compensation expense related to equity-based awards with performance conditions and terms that provide for a graded vesting schedule is recognized over the requisite service period for each separately vesting tranche of the award, and is based on the probable outcome of the performance conditions at each reporting date. The expense is adjusted for assumptions with respect to the estimated amount of awards that will be forfeited prior to vesting, and for employees who have met certain retirement eligibility criteria.

Dividend equivalents for certain equity-based awards are paid on stock units on a current basis prior to vesting and distribution. Compensation expense for common stock and cash awards granted to employees meeting early retirement eligibility criteria is fully expensed and accrued at the grant date.

Income Taxes

Income Taxes:

We use an asset and liability approach to account for income taxes. Our objective is to recognize the amount of taxes payable or refundable for the current year through charges or credits to the current tax provision, and to recognize deferred tax assets and liabilities for the future tax consequences resulting from temporary differences between the amounts reported in our consolidated financial statements and their respective tax bases. The measurement of tax assets and liabilities is based on enacted tax laws and applicable tax rates. The effects of a tax position on our consolidated financial statements are recognized when we believe it more likely than not that the position will be sustained. A deferred tax valuation allowance is established if it is considered more likely than not that all or a portion of the deferred tax assets will not be realized. Deferred tax assets and liabilities are netted within the same tax jurisdiction.

Earnings Per Share

Earnings Per Share:

Basic earnings per share, or EPS, is calculated pursuant to the "two-class" method, using net income available to common shareholders and the weighted-average number of common shares outstanding during the period. Diluted EPS is calculated pursuant to the two-class method, by dividing net income available to common shareholders by the weighted-average number of common shares outstanding for the period and the shares representing the dilutive effect of common stock options and other equity-based awards. The effect of common stock options and other equity-based awards is excluded from the calculation of diluted EPS in periods in which their effect would be anti-dilutive.

The two-class method requires the allocation of undistributed net income between common and participating shareholders. Net income available to common shareholders, presented separately in our consolidated statement of income, is the basis for the calculation of both basic and diluted EPS. Participating securities are composed of unvested restricted stock and director stock awards, which are equity-based awards that contain non-forfeitable rights to dividends, and are considered to participate with common shareholders in undistributed earnings.

Fair Value Measurements

Fair Value Measurements:

We carry certain of our financial assets and liabilities at fair value on a recurring basis. These financial assets and liabilities are composed of trading account assets, investment securities available for sale and various types of derivative financial instruments. In addition, we measure certain assets, such as goodwill, investment securities held to maturity and other long-lived assets, at fair value on a non-recurring basis to evaluate those assets for potential impairment. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

We categorize our financial assets and liabilities into the following fair value hierarchy:

Level 1 – Financial assets and liabilities with values based on unadjusted quoted prices for identical assets or liabilities in an active market. Examples of level 1 financial instruments include active exchange-traded equity securities and certain U.S. government 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. Examples of level 2 financial instruments include various types of fixed-income investment securities and interest-rate and foreign exchange derivative instruments. Pricing models are utilized to estimate fair value for certain financial assets and liabilities categorized in level 2.

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 fair value measurement. These inputs reflect management's judgment about the assumptions that a market participant would use in pricing the asset or liability, and are based on the best available information, some of which is internally developed. Examples of level 3 financial instruments include certain asset- and mortgage-backed securities and certain derivative instruments with little or no market activity and a resulting lack of price transparency.

When determining the fair value measurements for financial assets and liabilities carried at fair value on a recurring basis, we consider the principal or most advantageous market in which we would transact and consider assumptions that market participants would use when pricing the asset or liability. When possible, we look to active and observable markets to price identical assets or liabilities. When identical assets and liabilities are not traded in active markets, we look to market observable data for similar assets and liabilities. Nevertheless, certain assets and liabilities are not actively traded in observable markets, and we use alternative valuation techniques to derive fair value measurements.

Variable Interest Entities

Variable Interest Entities:

We are involved in the normal course of our business with various types of special purpose entities, some of which are variable interest entities, or VIEs, as defined by GAAP. We also 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 entities are considered to be VIEs. 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.

We use special purpose entities to structure and sell certificated interests in pools of tax-exempt investment-grade assets, principally to our mutual fund clients. These trusts are recorded in our consolidated financial statements. We transfer assets to these trusts, which are legally isolated from us, from our investment securities portfolio at adjusted book value. 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. The investment securities of the trusts are carried at fair value in investment securities available for sale. The certificated interests are carried at the amount owed to the third-party investors in other short-term borrowings. The interest revenue and interest expense generated by the investments and certificated interests, respectively, are recorded as components of net interest revenue when earned or incurred.

Derivative Financial Instruments

Derivative Financial Instruments:

A derivative financial instrument is a financial instrument or other contract which has one or more referenced indices and one or more notional amounts, either no initial net investment or a smaller initial net investment than would be expected for similar types of contracts, and which requires or permits net settlement. Derivatives that we enter into include forwards, futures, swaps, options and other instruments with similar characteristics.

We record derivatives in our consolidated statement of condition at their fair value. On the date a derivative contract is entered into, we designate the derivative as: (1) a hedge of the fair value of a recognized fixed-rate asset or liability or of an unrecognized firm commitment (a "fair value" hedge); (2) a hedge of a forecasted transaction or of the variability of cash flows to be received or paid related to a recognized variable-rate asset or liability (a "cash flow" hedge); (3) a foreign currency fair value or cash flow hedge (a "foreign currency" hedge); (4) a hedge of a net investment in a non-U.S. operation; or (5) a derivative utilized in either our trading activities or in our asset and liability management activities that is not accounted for as a hedge of an asset or liability.

Changes in the fair value of a derivative that is highly effective—and that is designated and qualifies as a fair value hedge—are recorded currently in processing fees and other revenue, along with the changes in fair value of the hedged asset or liability attributable to the hedged risk. Changes in the fair value of a derivative that is highly effective—and that is designated and qualifies as a cash flow hedge—are recorded, net of tax, in other comprehensive income, until earnings are affected by the hedged cash flows (e.g., when periodic settlements on a variable-rate asset or liability are recorded in earnings). Ineffectiveness of cash flow hedges, defined as the extent to which the changes in fair value of the derivative exceed the variability of cash flows of the forecasted transaction, is recorded in processing fees and other revenue.

Changes in the fair value of a derivative that is highly effective—and that is designated and qualifies as a foreign currency hedge—are recorded currently either in processing fees and other revenue or in other comprehensive income, net of tax, depending on whether the hedge transaction meets the criteria for a fair value or a cash flow hedge. If, however, a derivative is used as a hedge of a net investment in a non-U.S. operation, its changes in fair value, to the extent effective as a hedge, are recorded, net of tax, in the foreign currency translation component of other comprehensive income. Lastly, entire changes in the fair value of derivatives utilized in our trading activities are recorded in trading services revenue, and entire changes in the fair value of derivatives utilized in our asset and liability management activities are recorded in processing fees and other revenue.

At both the inception of the hedge and on an ongoing basis, we formally assess and document the effectiveness of a derivative designated as a hedge in offsetting changes in the fair value of hedged items and the likelihood that the derivative will be an effective hedge in future periods. We discontinue hedge accounting prospectively when we determine that the derivative is no longer highly effective in offsetting changes in fair value or cash flows of the underlying risk being hedged, the derivative expires, terminates or is sold, or management discontinues the hedge designation.

Unrealized gains and losses on foreign exchange and interest-rate contracts are reported at fair value in our consolidated statement of condition as a component of other assets and other liabilities, respectively, on a gross basis, except where such gains and losses arise from contracts covered by qualifying master netting agreements.

Recent Accounting Developments

Recent Accounting Developments:

The FASB is currently deliberating potentially significant changes to the U.S. accounting framework as part of an overall convergence effort with the International Accounting Standards Board under a previously signed memorandum of understanding. Some of these proposed changes have been exposed for comment, while others are expected to be exposed for comment over the next six to twelve months. These new proposals include potential changes to the accounting for financial instruments and hedging, the accounting for leases, revenue recognition and financial statement presentation. Once these proposed changes are finalized, we will disclose their nature and potential effect, if any, on our consolidated financial statements in our future filings. These proposed changes may have a material effect on our consolidated financial statements.

In September 2011, the FASB issued an amendment to GAAP that modifies existing guidance with respect to impairment of goodwill. The amendment provides companies with an option to perform a qualitative assessment to determine whether further impairment testing is necessary. The amendment is effective, for State Street, for interim and annual periods beginning on January 1, 2012. Adoption of the amendment is not expected to have a material effect on our consolidated financial statements.

In June 2011, the FASB issued an amendment to GAAP that eliminates the option to report other comprehensive income and its components in the statement of changes in shareholders' equity. Instead, an entity can elect to present the components of net income and other comprehensive income in either one continuous statement, referred to as the statement of comprehensive income, or in two separate, but consecutive statements. The amendment does not change which items are reported in other comprehensive income or the requirement to report reclassifications of items from other comprehensive income to net income. The amendment is effective, for State Street, for interim and annual periods beginning on January 1, 2012, and is required to be applied retrospectively. We are currently evaluating the options for presentation of other comprehensive income permitted by the amendment.

In May 2011, the FASB issued an amendment to GAAP associated with fair value measurement and related disclosures. While the amendment is not expected to significantly affect current practice, it clarifies the FASB's intent about the application of existing fair value measurement requirements, and requires the disclosure of additional quantitative information about fair value measurements. The amendment includes guidance about, among other things, the determination of a principal market and the measurement of fair value of instruments with offsetting market or counterparty credit risks. The amendment is effective, for State Street, for interim and annual periods beginning on January 1, 2012, and is required to be applied prospectively. Adoption of the amendment is not expected to have a material effect on our consolidated financial statements from a fair value measurement perspective. However, adoption is expected to result in additional disclosures in our consolidated financial statements.

In April 2011, the FASB issued an amendment to GAAP that eliminates the requirement to consider collateral maintenance when determining whether a transfer of assets subject to a repurchase arrangement is accounted for as a sale or as a secured borrowing. The amendment is effective prospectively, for State Street, for new transactions and modifications of existing transactions that occur on or after January 1, 2012. Adoption of the amendment is not expected to have a material effect on our consolidated financial statements, since we currently account for repurchase agreements as secured borrowings.