Schedule II - Valuation And Qualifying Accounts And Reserves (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Valuation And Qualifying Accounts And Reserves [Abstract]
Balance at Beginning of Period	$ 5,083	$ 5,186	$ 4,893
Additions Charged to Costs And Expenses	260	0	975
Deductions And Net Write-Offs	0	(103)	(682)
Balance at End of Period	$ 5,343	$ 5,083	$ 5,186