Goodwill (Details) (USD $) In Thousands	9 Months Ended		1 Months Ended	9 Months Ended		9 Months Ended		9 Months Ended
Sep. 30, 2011	Dec. 31, 2010	May 31, 2011 RP Data [Member] Data and Analytics [Member]	Sep. 30, 2011 RP Data [Member] Data and Analytics [Member]	Sep. 30, 2011 Data and Analytics [Member]	Dec. 31, 2010 Data and Analytics [Member]	Sep. 30, 2011 Business and Information Services [Member]	Dec. 31, 2010 Business and Information Services [Member]	Sep. 30, 2011 Business and Information Services [Member] Dorado Network Systems [Member]
Goodwill [Roll Forward]
Goodwill		$ 1,297,413				$ 603,516		$ 693,897
Accumulated impairment losses		(7,525)				(600)		(6,925)
Goodwill, net	1,468,663	1,289,888			762,793	602,916	705,870	686,972
Acquisitions	195,129		162,700	176,231					18,898
Other/post acquisition adjustments	(16,354)				(16,354)		0
Goodwill, net	$ 1,468,663	$ 1,289,888			$ 762,793	$ 602,916	$ 705,870	$ 686,972

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 increase (decrease) in the recorded value of goodwill for foreign currency translation adjustments and purchase accounting adjustments needed to revise the carrying amount of goodwill to fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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+ Details