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
Allowance for doubtful accounts
Valuation and qualifying accounts
Balance at Beginning of Year	$ 1,719	$ 1,379	$ 2,710
Additions	2,128	642	(763)
Deductions	1,065	302	568
Balance at End of Year	2,782	1,719	1,379
Allowance for sales discounts
Valuation and qualifying accounts
Balance at Beginning of Year	4,629	5,819	2,796
Additions	35,759	36,254	26,514
Deductions	36,552	37,444	23,491
Balance at End of Year	3,836	4,629	5,819
Allowance for sales returns
Valuation and qualifying accounts
Balance at Beginning of Year	11,313	4,039	3,235
Additions	53,165	37,355	20,726
Deductions	51,573	30,081	19,922
Balance at End of Year	12,905	11,313	4,039
Chargeback allowance
Valuation and qualifying accounts
Balance at Beginning of Year	4,031	2,535	3,049
Additions	5,879	1,744	(253)
Deductions	434	248	261
Balance at End of Year	$ 5,563	$ 4,031	$ 2,535