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	$ 1,379	$ 2,710	$ 2,482
Additions	642	(763)	399
Deductions	302	568	171
Balance at End of Year	1,719	1,379	2,710
Allowance for sales discounts
Valuation and qualifying accounts
Balance at Beginning of Year	5,819	2,796	4,241
Additions	36,254	26,514	22,630
Deductions	37,444	23,491	24,075
Balance at End of Year	4,629	5,819	2,796
Allowance for sales returns
Valuation and qualifying accounts
Balance at Beginning of Year	4,039	3,235	2,335
Additions	37,355	20,726	15,947
Deductions	30,081	19,922	15,047
Balance at End of Year	11,313	4,039	3,235
Chargeback allowance
Valuation and qualifying accounts
Balance at Beginning of Year	2,535	3,049	1,648
Additions	1,744	(253)	1,644
Deductions	248	261	243
Balance at End of Year	$ 4,031	$ 2,535	$ 3,049