Other Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Other Accrued Liabilities [Abstract]
Accrued warranty, current, see Note 1	$ 1,021	$ 1,190	$ 1,094
Accrued taxes, net	1,371		1,023
Accrued sales return (1)	9,773	11,548
Other accrued liabilities	3,497		3,869
Total other accrued liabilities	15,662		22,032
Balance at beginning of year	16,046	11,781
Additions that reduce net sales	9,899	10,008
Deductions from reserves	(16,172)	(10,241)
Balance at end of period	$ 9,773	$ 11,548