Valuation And Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Allowance For Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 1,743	$ 1,971	$ 1,596
Additions Charged to Costs and Expenses	215	403	565
Deductions Returns and Write-Offs	(758)	(631)	(190)
Balance at End of Year	1,200	1,743	1,971
Income Tax Valuation Allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year		3,495	7,977
Additions Charged to Costs and Expenses			337
Deductions Returns and Write-Offs		(3,495)	(4,819)
Balance at End of Year			$ 3,495