Pledged Assets	6 Months Ended
Jun. 30, 2012
Pledged Assets	7. Pledged Assets – Certain of Northern Trust’s subsidiaries, as required or permitted by law, pledge assets to secure public and trust deposits, repurchase agreements, Federal Home Loan Bank borrowings, and for other purposes. At June 30, 2012, $25.1 billion ($22.0 billion of government sponsored agency and other securities, $365.5 million of obligations of states and political subdivisions, and $2.8 billion of loans) were pledged. This compares to $27.9 billion ($21.5 billion of government sponsored agency and other securities, $460.2 million of obligations of states and political subdivisions, and $6.0 billion of loans) at December 31, 2011. Collateral required for these purposes totaled $4.6 billion and $4.8 billion on June 30, 2012 and December 31, 2011, respectively. Included in the total pledged assets at June 30, 2012 and December 31, 2011 were available for sale securities with a total fair value of $218.3 million and $1.2 billion, respectively, which were pledged as collateral for agreements to repurchase securities sold transactions. The secured parties to these transactions have the right to repledge or sell these securities. Northern Trust is permitted to repledge or sell collateral from agreements to resell securities purchased transactions. The total fair value of accepted collateral as of June 30, 2012 and December 31, 2011 was $4.5 million and $74.7 million, respectively. There was no repledged or sold collateral at June 30, 2012 or December 31, 2011. Deposits maintained to meet Federal Reserve Bank reserve requirements averaged $1.0 billion and $1.1 billion for the three and six months ended June 30, 2012, respectively, and $238.4 million and $226.3 million for the three and six months ended June 30, 2011, respectively.

7. Pledged Assets – Certain of Northern Trust’s subsidiaries, as required or permitted by law, pledge assets to secure public and trust deposits, repurchase agreements, Federal Home Loan Bank borrowings, and for other purposes. At June 30, 2012, $25.1 billion ($22.0 billion of government sponsored agency and other securities, $365.5 million of obligations of states and political subdivisions, and $2.8 billion of loans) were pledged. This compares to $27.9 billion ($21.5 billion of government sponsored agency and other securities, $460.2 million of obligations of states and political subdivisions, and $6.0 billion of loans) at December 31, 2011. Collateral required for these purposes totaled $4.6 billion and $4.8 billion on June 30, 2012 and December 31, 2011, respectively. Included in the total pledged assets at June 30, 2012 and December 31, 2011 were available for sale securities with a total fair value of $218.3 million and $1.2 billion, respectively, which were pledged as collateral for agreements to repurchase securities sold transactions. The secured parties to these transactions have the right to repledge or sell these securities.

Northern Trust is permitted to repledge or sell collateral from agreements to resell securities purchased transactions. The total fair value of accepted collateral as of June 30, 2012 and December 31, 2011 was $4.5 million and $74.7 million, respectively. There was no repledged or sold collateral at June 30, 2012 or December 31, 2011. Deposits maintained to meet Federal Reserve Bank reserve requirements averaged $1.0 billion and $1.1 billion for the three and six months ended June 30, 2012, respectively, and $238.4 million and $226.3 million for the three and six months ended June 30, 2011, respectively.