Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2016	Oct. 03, 2015	Oct. 01, 2016	Oct. 03, 2015
Income Statement [Abstract]
Net sales	$ 367,988	$ 373,919	$ 997,846	$ 999,017
Cost of sales	135,645	140,283	385,168	379,009
Gross profit	232,343	233,636	612,678	620,008
Operating expenses:
Sales and marketing	158,024	156,899	443,477	424,029
General and administrative	28,278	27,817	86,202	79,951
Research and development	6,997	3,521	21,661	10,275
Total operating expenses	193,299	188,237	551,340	514,255
Operating income	39,044	45,399	61,338	105,753
Other (expense) income, net	(255)	78	(581)	364
Income before income taxes	38,789	45,477	60,757	106,117
Income tax expense	13,044	13,623	20,627	34,426
Net income	$ 25,745	$ 31,854	$ 40,130	$ 71,691
Basic net income per share:
Net income per share – basic	$ 0.56	$ 0.63	$ 0.86	$ 1.39
Weighted-average shares – basic	45,621,000	50,945,000	46,705,000	51,654,000
Diluted net income per share:
Net income per share – diluted	$ 0.56	$ 0.62	$ 0.85	$ 1.36
Weighted-average shares – diluted	46,350,000	51,701,000	47,413,000	52,524,000