Schedule II VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts
Valuation and qualifying accounts
Balance at Beginning of Year	$ 2,782	$ 1,719	$ 1,379
Additions	125	2,128	642
Deductions	868	1,065	302
Balance at End of Year	2,039	2,782	1,719
Allowance for sales discounts
Valuation and qualifying accounts
Balance at Beginning of Year	3,836	4,629	5,819
Additions	46,989	35,759	36,254
Deductions	47,285	36,552	37,444
Balance at End of Year	3,540	3,836	4,629
Allowance for sales returns
Valuation and qualifying accounts
Balance at Beginning of Year	12,905	11,313	4,039
Additions	67,800	53,165	37,355
Deductions	66,151	51,573	30,081
Balance at End of Year	14,554	12,905	11,313
Chargeback allowance
Valuation and qualifying accounts
Balance at Beginning of Year	5,563	4,031	2,535
Additions	187	5,879	1,744
Deductions	815	4,347	248
Balance at End of Year	$ 4,935	$ 5,563	$ 4,031