Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2016	Jul. 04, 2015	Jul. 02, 2016	Jul. 04, 2015
Income Statement [Abstract]
Net sales	$ 276,878	$ 275,289	$ 629,858	$ 625,098
Cost of sales	105,617	104,750	249,523	238,726
Gross profit	171,261	170,539	380,335	386,372
Operating expenses:
Sales and marketing	134,785	126,627	285,453	267,130
General and administrative	27,018	23,880	57,924	52,134
Research and development	7,062	3,403	14,664	6,754
Total operating expenses	168,865	153,910	358,041	326,018
Operating income	2,396	16,629	22,294	60,354
Other (expense) income, net	(229)	133	(326)	286
Income before income taxes	2,167	16,762	21,968	60,640
Income tax expense	751	5,724	7,583	20,803
Net income	$ 1,416	$ 11,038	$ 14,385	$ 39,837
Basic net income per share:
Net income per share – basic	$ 0.03	$ 0.21	$ 0.30	$ 0.77
Weighted-average shares – basic	46,394,000	51,672,000	47,247,000	52,009,000
Diluted net income per share:
Net income per share – diluted	$ 0.03	$ 0.21	$ 0.30	$ 0.75
Weighted-average shares – diluted	47,044,000	52,544,000	47,945,000	52,935,000