Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2017	Apr. 02, 2016
Income Statement [Abstract]
Net sales	$ 393,899	$ 352,980
Cost of sales	147,440	143,906
Gross profit	246,459	209,074
Operating expenses:
Sales and marketing	169,266	150,668
General and administrative	33,769	30,906
Research and development	7,596	7,602
Total operating expenses	210,631	189,176
Operating income	35,828	19,898
Other expense, net	(138)	(97)
Income before income taxes	35,690	19,801
Income tax expense	11,229	6,832
Net income	$ 24,461	$ 12,969
Basic net income per share:
Net income per share – basic	$ 0.57	$ 0.27
Weighted-average shares – basic	42,750,000	48,100,000
Diluted net income per share:
Net income per share – diluted	$ 0.56	$ 0.27
Weighted-average shares – diluted	43,712,000	48,845,000