Recent Accounting Pronouncements	9 Months Ended
Sep. 30, 2011
Recent Accounting Pronouncements	2. Recent Accounting Pronouncements – In September 2011, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2011-08, “Testing Goodwill for Impairment”. The ASU provides the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the results of the qualitative analysis indicate it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, the quantitative two-step impairment test, which is required under current U.S. GAAP, would not be necessary. The ASU is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011. The adoption of this ASU by Northern Trust, effective January 1, 2012, is not expected to have an impact on Northern Trust’s consolidated financial position or results of operations.

Recent Accounting Pronouncements

9 Months Ended

Sep. 30, 2011

2. Recent Accounting Pronouncements – In September 2011, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2011-08, “Testing Goodwill for Impairment”. The ASU provides the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the results of the qualitative analysis indicate it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, the quantitative two-step impairment test, which is required under current U.S. GAAP, would not be necessary. The ASU is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011. The adoption of this ASU by Northern Trust, effective January 1, 2012, is not expected to have an impact on Northern Trust’s consolidated financial position or results of operations.