Other Expenses	12 Months Ended
Dec. 31, 2012
Operating Costs and Expenses [Abstract]
Other Expenses	Other Expenses As a result of the 2008 Lehman Brothers bankruptcy, we had various claims against Lehman Brothers entities in bankruptcy proceedings in the U.S. and the U.K. We also had amounts asserted as owed, or return obligations, to Lehman Brothers entities. The various claims and amounts owed arose from transactions that existed at the time Lehman Brothers entered bankruptcy, including foreign exchange transactions, securities lending arrangements and repurchase agreements. During 2011, we reached an agreement with certain Lehman Brothers estates in the U.S. to resolve the value of deficiency claims arising out of indemnified repurchase transactions in the U.S., and the bankruptcy court allowed those claims in the amount of $400 million. In 2012, we received two distributions totaling $338 million. In September 2012, we reached an agreement to settle the claims against the Lehman Brothers estate in the U.K. related to the close-out of securities lending and repurchase arrangements. This settlement resulted in a return obligation for us and a certified claim against the Lehman Brothers estate, and resolved the contingent nature of our rights and obligations with the Lehman Brothers estate. In connection with our resolution of the indemnified repurchase and securities lending claims in the U.S. and the U.K., we recognized a benefit of approximately $362 million in our consolidated statement of income in 2012. Both certified claims retained as part of the settlement agreements were subsequently sold at their respective fair values, resulting in an additional gain of approximately $10 million, which was also recorded in our consolidated statement of income in 2012. In 2010, we recorded an aggregate pre-tax charge of $414 million, including associated legal costs of $9 million, in our consolidated statement of income with respect to the cash collateral pools underlying SSgA-managed investment funds engaged in securities lending, as well as the cash collateral pools underlying our agency lending program. In connection with the charge, we made a one-time cash contribution of $330 million to the cash collateral pools and liquidating trusts underlying the SSgA lending funds. In light of our assessment with respect to previously disclosed asserted and unasserted claims and our evaluation of the ultimate resolution of such claims, as well as the effect of the redemption restrictions originally imposed by SSgA on the lending funds and other considerations, we elected to make the cash contribution, which restored the net asset value per unit of the underlying cash collateral pools to $1.00 as of June 30, 2010. As a result of this action, SSgA removed the redemption restrictions from the SSgA lending funds in August 2010. The pre-tax charge also included the establishment of a $75 million reserve to address potential inconsistencies in connection with our implementation of the redemption restrictions applicable to the collateral pools underlying our agency lending program. This charge was based on the results of a review of our implementation of the redemption restrictions with respect to participants in the agency lending collateral pools, and our assessment of the amount required to compensate clients for the dilutive effect of redemptions which may not have been consistent with the intent of the policy. In May 2011, we distributed substantially all of the reserve.

Other Expenses

As a result of the 2008 Lehman Brothers bankruptcy, we had various claims against Lehman Brothers entities in bankruptcy proceedings in the U.S. and the U.K. We also had amounts asserted as owed, or return obligations, to Lehman Brothers entities. The various claims and amounts owed arose from transactions that existed at the time Lehman Brothers entered bankruptcy, including foreign exchange transactions, securities lending arrangements and repurchase agreements. During 2011, we reached an agreement with certain Lehman Brothers estates in the U.S. to resolve the value of deficiency claims arising out of indemnified repurchase transactions in the U.S., and the bankruptcy court allowed those claims in the amount of $400 million. In 2012, we received two distributions totaling $338 million.

In September 2012, we reached an agreement to settle the claims against the Lehman Brothers estate in the U.K. related to the close-out of securities lending and repurchase arrangements. This settlement resulted in a return obligation for us and a certified claim against the Lehman Brothers estate, and resolved the contingent nature of our rights and obligations with the Lehman Brothers estate.

In connection with our resolution of the indemnified repurchase and securities lending claims in the U.S. and the U.K., we recognized a benefit of approximately $362 million in our consolidated statement of income in 2012. Both certified claims retained as part of the settlement agreements were subsequently sold at their respective fair values, resulting in an additional gain of approximately $10 million, which was also recorded in our consolidated statement of income in 2012.

In 2010, we recorded an aggregate pre-tax charge of $414 million, including associated legal costs of $9 million, in our consolidated statement of income with respect to the cash collateral pools underlying SSgA-managed investment funds engaged in securities lending, as well as the cash collateral pools underlying our agency lending program. In connection with the charge, we made a one-time cash contribution of $330 million to the cash collateral pools and liquidating trusts underlying the SSgA lending funds. In light of our assessment with respect to previously disclosed asserted and unasserted claims and our evaluation of the ultimate resolution of such claims, as well as the effect of the redemption restrictions originally imposed by SSgA on the lending funds and other considerations, we elected to make the cash contribution, which restored the net asset value per unit of the underlying cash collateral pools to $1.00 as of June 30, 2010. As a result of this action, SSgA removed the redemption restrictions from the SSgA lending funds in August 2010.

The pre-tax charge also included the establishment of a $75 million reserve to address potential inconsistencies in connection with our implementation of the redemption restrictions applicable to the collateral pools underlying our agency lending program. This charge was based on the results of a review of our implementation of the redemption restrictions with respect to participants in the agency lending collateral pools, and our assessment of the amount required to compensate clients for the dilutive effect of redemptions which may not have been consistent with the intent of the policy. In May 2011, we distributed substantially all of the reserve.