Intangible Assets and Goodwill (Details) (USD $)	3 Months Ended		6 Months Ended														3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Customer Relationships [Member]	Dec. 31, 2012 Customer Relationships [Member]	Jun. 30, 2013 Supplier Relationships [Member]	Dec. 31, 2012 Supplier Relationships [Member]	Jun. 30, 2013 Software And Technology [Member]	Dec. 31, 2012 Software And Technology [Member]	Jun. 30, 2013 Trademark And Trade Name [Member]	Dec. 31, 2012 Trademark And Trade Name [Member]	Jun. 30, 2013 Noncompete Agreements [Member]	Dec. 31, 2012 Noncompete Agreements [Member]	Jun. 30, 2013 Total Intangible Assets [Member]	Dec. 31, 2012 Total Intangible Assets [Member]	Jun. 30, 2013 Management Services [Member]
Finite lived intangible assets
Finite lived intangible assets, gross					$ 403,542,000	$ 407,901,000	$ 29,000,000	$ 29,000,000	$ 167,598,000	$ 169,632,000	$ 34,582,000	$ 35,078,000	$ 7,288,000	$ 7,471,000	$ 642,010,000	$ 649,082,000
Finite lived intangible assets accumulated amortization					(281,707,000)	(269,100,000)	(23,563,000)	(22,113,000)	(153,294,000)	(151,628,000)	(32,748,000)	(32,615,000)	(7,247,000)	(7,412,000)	(498,559,000)	(482,868,000)
Finite lived intangible assets, net	143,451,000		143,451,000		121,835,000	138,801,000	5,437,000	6,887,000	14,304,000	18,004,000	1,834,000	2,463,000	41,000	59,000	143,451,000	166,214,000
Finite Lived Intangible Assets Amortization Expense	9,000,000	11,000,000	19,000,000	23,000,000
Document Period End Date			Jun. 30, 2013
Goodwill, Impairment Loss	$ 100,253,000																$ 100,253,000