Schedule II - Valuation and Qualifying Accoutns (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Valuation Allowance of Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance Period Start	$ 37,015		$ 37,926		$ 40,663
Additions Charged (Credited) to Costs and Expenses	6,356		(2,631)		6,602
Deductions	0		0		(9,339)
Other	5,555	[1]	1,720	[1]	0	[1]
Valuation Allowances and Reserves, Balance Period End	48,926		37,015		37,926
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance Period Start	25,052		23,100		19,567
Additions Charged (Credited) to Costs and Expenses	15,112		7,984		7,783
Deductions	(6,905)		(6,032)		(4,250)
Valuation Allowances and Reserves, Balance Period End	$ 33,259		$ 25,052		$ 23,100

[1] Due to acquisitions.