Goodwill and Intangible Assets (Details) (USD $) In Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2011	Dec. 31, 2010	Dec. 31, 2009
Goodwill
Goodwill, Beginning balance	$ 279,434	$ 337,765
Acquired goodwill	64	2,292
Sale of discontinued operations, accumulated impairment loss		53,840
Goodwill, Ending balance	279,498	279,434
Sale of discontinued operation goodwill, net		(6,783)
Impairment losses gross carrying amount		(60,623)
Accumulated impairment loss	(139,414)	(139,414)	(193,254)
Goodwill	$ 140,084	$ 140,020	$ 144,511

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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