Acquisitions	12 Months Ended
Dec. 31, 2011
Acquisitions [Abstract]
Acquisitions	Note 2. Acquisitions On November 3, 2011 and October 3, 2011, respectively, we completed our acquisitions of Pulse Trading, Inc., a full- service agency brokerage firm based in Boston, Massachusetts, and Complementa Investment-Controlling AG, an investment performance measurement and analytics firm based in Switzerland. Both transactions were cash acquisitions financed through available capital. Pulse Trading offers a broad range of services to institutional investors, including trading, independent research, portfolio consulting and trading technology, and has offices in Boston, Massachusetts; New York City, New York; San Francisco, California and St. Louis, Missouri. We acquired Pulse Trading to enhance the electronic trading technology we provide to our institutional clients. Our acquisition of Pulse Trading includes its institutional equities business. Complementa provides services associated with asset consolidation, investment performance measurement, investment controlling and investment consulting for institutional and large private investors, and has offices in Switzerland, Germany and Liechtenstein. We acquired Complementa to enhance our investment analytics capabilities and our overall presence in key markets in Europe. Our acquisition of Complementa includes its wholly-owned asset management software provider. In connection with these two acquisitions, we recorded aggregate goodwill of approximately $68 million, substantially all of which is not expected to be tax deductible, and aggregate other intangible assets of approximately $67 million in our consolidated statement of condition. The purchase price allocations for the acquisitions were preliminary as of December 31, 2011, and are subject to future adjustment as information needed to measure the acquisition-date fair values of certain identifiable assets acquired and liabilities assumed is obtained. Accordingly, the measurement periods for both acquisitions remained open as of December 31, 2011. Results of operations of the acquired Pulse Trading and Complementa businesses are included in our consolidated financial statements beginning on their respective dates of acquisition. On January 10, 2011, we completed our acquisition of Bank of Ireland's asset management business, or BIAM, in a cash acquisition financed through available capital. We acquired BIAM to enhance SSgA's range of investment management solutions and expand our overall presence in Ireland, where we already provide services to institutional clients, to provide a range of investment management products. In connection with our acquisition of BIAM, we recorded approximately $31 million of goodwill, substantially all of which is not expected to be tax deductible, and approximately $27 million of other intangible assets in our consolidated statement of condition, and added approximately $23 billion to our assets under management as of March 31, 2011. The assets under management are not recorded in our consolidated financial statements. Results of operations of the acquired BIAM business are included in our consolidated financial statements beginning on January 10, 2011. In May 2010, we completed our acquisition of Intesa Sanpaolo's securities services business in a cash acquisition financed through available capital. Results of operations of the acquired Intesa business have been included in our consolidated financial statements from the date the acquisition was completed. In connection with the acquisition, the assets acquired, liabilities assumed and consideration paid were recorded in our consolidated statement of condition at their estimated fair values on the acquisition date. These assets included $932 million of goodwill and $848 million of other intangible assets, including assets related to client relationships and core deposits. The goodwill, substantially all of which is not expected to be tax deductible, represents the expected long-term value of cost savings, growth opportunities and business efficiencies created by the integration of the acquired Intesa business. We also added approximately $564 billion to our assets under custody and administration as of June 30, 2010. These assets are not recorded in our consolidated financial statements. With respect to the acquired Intesa business, we may be entitled to a return of a portion of the purchase price, should we lose the business of certain key clients during a defined period subsequent to the closing of the transaction. This contingent asset, which was approximately $53 million as of December 31, 2011, compared to approximately $72 million as of December 31, 2010, will be re-measured to fair value at each reporting date through the end of the defined purchase price adjustment period, with any changes in its fair value recorded in our consolidated statement of income. During the fourth quarter of 2010, Italian tax authorities issued an assessment for taxes, penalties and interest for corporate income tax, regional tax and withholding taxes of approximately €130 million to an Italian banking subsidiary acquired by us in connection with the acquisition. The assessment related to 2005, a pre-acquisition tax year. State Street was indemnified for this liability under the acquisition agreement, which further required the indemnity obligation to be collateralized in the event of a tax assessment and provided that the seller had the right to control the defense of indemnified claims. During the fourth quarter of 2011, the Italian banking subsidiary reached a settlement agreement with the Italian tax authorities regarding these assessments, as well as the Italian tax authorities' audit of the 2006 tax year. As such, we recorded the impact of the tax settlement and associated indemnification in our 2011 consolidated financial statements. In April 2010, we completed our acquisition of Mourant International Finance Administration, or MIFA, in a cash transaction financed through available capital. We acquired MIFA to enhance our position as an administrator of alternative investments and to expand our presence outside of the U.S. In connection with our acquisition of MIFA, a provider of fund administration services, particularly for alternative investment funds such as private equity, real estate and hedge funds with operations in Jersey in the Channel Islands, Dublin, Singapore and New York, we recorded $73 million of goodwill, substantially all of which is not expected to be tax deductible, and $59 million of other intangible assets in our consolidated statement of condition, and added $122 billion to our assets under administration as of June 30, 2010. The assets under administration are not recorded in our consolidated financial statements. Results of operations of the acquired MIFA business are included in our consolidated financial statements beginning on April 1, 2010.

Note 2. Acquisitions

On November 3, 2011 and October 3, 2011, respectively, we completed our acquisitions of Pulse Trading, Inc., a full- service agency brokerage firm based in Boston, Massachusetts, and Complementa Investment-Controlling AG, an investment performance measurement and analytics firm based in Switzerland. Both transactions were cash acquisitions financed through available capital.

Pulse Trading offers a broad range of services to institutional investors, including trading, independent research, portfolio consulting and trading technology, and has offices in Boston, Massachusetts; New York City, New York; San Francisco, California and St. Louis, Missouri. We acquired Pulse Trading to enhance the electronic trading technology we provide to our institutional clients. Our acquisition of Pulse Trading includes its institutional equities business. Complementa provides services associated with asset consolidation, investment performance measurement, investment controlling and investment consulting for institutional and large private investors, and has offices in Switzerland, Germany and Liechtenstein. We acquired Complementa to enhance our investment analytics capabilities and our overall presence in key markets in Europe. Our acquisition of Complementa includes its wholly-owned asset management software provider.

In connection with these two acquisitions, we recorded aggregate goodwill of approximately $68 million, substantially all of which is not expected to be tax deductible, and aggregate other intangible assets of approximately $67 million in our consolidated statement of condition. The purchase price allocations for the acquisitions were preliminary as of December 31, 2011, and are subject to future adjustment as information needed to measure the acquisition-date fair values of certain identifiable assets acquired and liabilities assumed is obtained. Accordingly, the measurement periods for both acquisitions remained open as of December 31, 2011. Results of operations of the acquired Pulse Trading and Complementa businesses are included in our consolidated financial statements beginning on their respective dates of acquisition.

On January 10, 2011, we completed our acquisition of Bank of Ireland's asset management business, or BIAM, in a cash acquisition financed through available capital. We acquired BIAM to enhance SSgA's range of investment management solutions and expand our overall presence in Ireland, where we already provide services to institutional clients, to provide a range of investment management products. In connection with our acquisition of BIAM, we recorded approximately $31 million of goodwill, substantially all of which is not expected to be tax deductible, and approximately $27 million of other intangible assets in our consolidated statement of condition, and added approximately $23 billion to our assets under management as of March 31, 2011. The assets under management are not recorded in our consolidated financial statements. Results of operations of the acquired BIAM business are included in our consolidated financial statements beginning on January 10, 2011.

In May 2010, we completed our acquisition of Intesa Sanpaolo's securities services business in a cash acquisition financed through available capital. Results of operations of the acquired Intesa business have been included in our consolidated financial statements from the date the acquisition was completed. In connection with the acquisition, the assets acquired, liabilities assumed and consideration paid were recorded in our consolidated statement of condition at their estimated fair values on the acquisition date. These assets included $932 million of goodwill and $848 million of other intangible assets, including assets related to client relationships and core deposits. The goodwill, substantially all of which is not expected to be tax deductible, represents the expected long-term value of cost savings, growth opportunities and business efficiencies created by the integration of the acquired Intesa business. We also added approximately $564 billion to our assets under custody and administration as of June 30, 2010. These assets are not recorded in our consolidated financial statements.

With respect to the acquired Intesa business, we may be entitled to a return of a portion of the purchase price, should we lose the business of certain key clients during a defined period subsequent to the closing of the transaction. This contingent asset, which was approximately $53 million as of December 31, 2011, compared to approximately $72 million as of December 31, 2010, will be re-measured to fair value at each reporting date through the end of the defined purchase price adjustment period, with any changes in its fair value recorded in our consolidated statement of income.

During the fourth quarter of 2010, Italian tax authorities issued an assessment for taxes, penalties and interest for corporate income tax, regional tax and withholding taxes of approximately €130 million to an Italian banking subsidiary acquired by us in connection with the acquisition. The assessment related to 2005, a pre-acquisition tax year. State Street was indemnified for this liability under the acquisition agreement, which further required the indemnity obligation to be collateralized in the event of a tax assessment and provided that the seller had the right to control the defense of indemnified claims. During the fourth quarter of 2011, the Italian banking subsidiary reached a settlement agreement with the Italian tax authorities regarding these assessments, as well as the Italian tax authorities' audit of the 2006 tax year. As such, we recorded the impact of the tax settlement and associated indemnification in our 2011 consolidated financial statements.

In April 2010, we completed our acquisition of Mourant International Finance Administration, or MIFA, in a cash transaction financed through available capital. We acquired MIFA to enhance our position as an administrator of alternative investments and to expand our presence outside of the U.S. In connection with our acquisition of MIFA, a provider of fund administration services, particularly for alternative investment funds such as private equity, real estate and hedge funds with operations in Jersey in the Channel Islands, Dublin, Singapore and New York, we recorded $73 million of goodwill, substantially all of which is not expected to be tax deductible, and $59 million of other intangible assets in our consolidated statement of condition, and added $122 billion to our assets under administration as of June 30, 2010. The assets under administration are not recorded in our consolidated financial statements. Results of operations of the acquired MIFA business are included in our consolidated financial statements beginning on April 1, 2010.