Goodwill And Intangible Assets (Schedule Of Intangible Assets And Goodwill) (Details) (USD $) In Thousands	9 Months Ended	12 Months Ended							9 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 Goodwill [Member]	Dec. 31, 2010 Goodwill [Member]	Dec. 31, 2009 Goodwill [Member]	Sep. 30, 2011 Intangible Assets With Indefinite Lives [Member]	Dec. 31, 2010 Intangible Assets With Indefinite Lives [Member]	Dec. 31, 2009 Intangible Assets With Indefinite Lives [Member]	Sep. 30, 2011 Intangible Assets With Finite Lives [Member]	Dec. 31, 2010 Intangible Assets With Finite Lives [Member]
Goodwill And Intangible Assets [Line Items]
Goodwill and Intangible Assets, Net	$ 325,252	$ 328,735	$ 268,376	$ 268,376	$ 268,376	$ 23,920	$ 23,920	$ 23,920	$ 32,956	$ 36,439
Amortization	(2,300)	(3,483)							(2,300)	(3,483)
Goodwill and Intangible Assets, Net	322,952	325,252	268,376	268,376	268,376	23,920	23,920	23,920	30,656	32,956
Goodwill and Intangible Assets, Gross	340,652		268,532			23,920			48,200
Accumulated amortization	(10,678)								(10,678)
Accumulated impairments	$ (7,022)		$ (156)						$ (6,866)