SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Year	$ 8,488	$ 7,588	$ 6,662
Additions Charged to Costs and Expenses	941	900	6,818
Deductions	(146)		(5,892)
Balance at End of Year	9,283	8,488	7,588
Allowance for inventory obsolescence
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Year	8,248	7,541	6,615
Additions Charged to Costs and Expenses	941	707	926
Balance at End of Year	9,189	8,248	7,541
Allowance for doubtful accounts receivable
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Year	240	47	47
Additions Charged to Costs and Expenses		193	5,892
Deductions	(146)		(5,892)
Balance at End of Year	$ 94	$ 240	$ 47