Valuation And Qualifying Accounts (Details) (Accounts Receivable Allowance For Doubtful Accounts [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Accounts Receivable Allowance For Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 9,710		$ 9,167		$ 14,438
Charged to Expense	1,321		917		1,970
Additions/(Deductions)	(62)	[1]	(374)	[1]	(7,241)	[1]
Balance at End of Year	$ 10,969		$ 9,710		$ 9,167

[1] Primarily accounts receivable written off during the period.