Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012
Income Statement [Abstract]
Net sales	$ 207,391	$ 205,219	$ 465,628	$ 467,602
Cost of sales	75,993	73,648	170,814	171,732
Gross profit	131,398	131,571	294,814	295,870
Operating Expenses:
Sales and marketing	98,357	88,240	208,170	194,425
General and administrative	15,359	16,220	31,540	33,149
Research and development	2,560	1,256	5,116	2,546
Asset impairment charges	0	0	(391)	5,595
Asset impairment charges	15	3	45	7
Total operating expenses	116,291	105,719	244,480	235,722
Operating income	15,107	25,852	50,334	60,148
Other income, net	78	48	169	55
Income before income taxes	15,185	25,900	50,503	60,203
Income tax expense	5,259	8,927	17,106	20,813
Net income	$ 9,926	$ 16,973	$ 33,397	$ 39,390
Basic net income per share:
Net income per share – basic	$ 0.18	$ 0.30	$ 0.61	$ 0.71
Weighted-average shares – basic	55,029	55,719	55,062	55,680
Diluted net income per share:
Net income per share – diluted	$ 0.18	$ 0.30	$ 0.60	$ 0.69
Weighted-average shares – diluted	55,987	57,394	56,101	57,367