SCHEDULE II 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
Valuation and qualifying accounts
Balance at beginning of Year	$ 1,344	$ 4,667	$ 4,368
Charged to Costs and Expenses	67	(81)	666
Deductions	420	3,242	367
Balance at End of Year	991	1,344	4,667
Allowance for sales discounts
Valuation and qualifying accounts
Balance at beginning of Year	1,181	1,908	1,556
Charged to Costs and Expenses	50	794	1,623
Deductions		1,521	1,271
Balance at End of Year	1,231	1,181	1,908
Allowance for deferred tax assets
Valuation and qualifying accounts
Balance at beginning of Year	7,167	4,888	2,376
Charged to Costs and Expenses	1,081	3,344	2,685
Deductions	1,970	1,065	173
Balance at End of Year	$ 6,279	$ 7,167	$ 4,888