Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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+ Details

- Definition

The aggregate amount of goodwill acquired in the period and allocated to the reportable segment. The value is stated at fair value based on the purchase price allocation.

+ References+ Details

- Definition

Loss recognized during the period that results from the write-down of goodwill after comparing the implied fair value of reporting unit goodwill with the carrying amount of that goodwill. Goodwill is assessed at least annually for impairment.

+ References

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+ Details

Goodwill and Other Intangibles (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended				3 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011 U.S. Operations	Jun. 30, 2011 U.S. Operations	Mar. 31, 2010 Other reporting units	Jun. 30, 2011 Other reporting units	Jun. 30, 2011 European Operations.	Jun. 30, 2011 Asia Pacific Operations.	Dec. 31, 2010 Asia Pacific Operations.	Jun. 30, 2010 Australia	Jun. 30, 2010 Australia
Changes in the carrying amount of goodwill
Balance at the beginning the period			$ 468,479		$ 470,100	$ 439,294			$ 28,484	$ 701	$ 701
Impairment loss	225,035	5,375	225,035	5,375	225,000	225,035						5,400	5,400
Acquisition of Ross Smith Energy			30,715			30,715
ITG Investment Research price adjustment			144			144
Currency translation adjustment			(14)						(14)
Balance at the end the period	$ 274,289		$ 274,289		$ 245,118	$ 245,118			$ 28,470	$ 701	$ 701
Percentage of the excess of fair value of goodwill over carrying value, low end of range (as a percent)							20.00%
Percentage excess of fair value of goodwill over carrying value, high end of the range (as a percent)							167.00%
Number of reportable units with possible goodwill impairment								1