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
Allowance for doubtful accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year			$ 92
Utilizations			(92)
Allowance for inventory reserves [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	3,982	3,336	4,989
Charged to Costs and Expenses, Net of Reversals	2,766	1,012	2,109
Utilizations	(4,309)	(366)	(3,762)
Balance at End of Year	$ 2,439	$ 3,982	$ 3,336