Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Apr. 03, 2021	Mar. 28, 2020
Income Statement [Abstract]
Net sales	$ 568,256	$ 472,566
Cost of sales	212,338	170,435
Gross profit	355,918	302,131
Operating expenses:
Sales and marketing	223,617	207,744
General and administrative	42,592	31,072
Research and development	13,286	10,501
Total operating expenses	279,495	249,317
Operating income	76,423	52,814
Interest expense, net	977	2,344
Income before income taxes	75,446	50,470
Income tax expense	8,812	11,330
Net income	$ 66,634	$ 39,140
Basic net income per share:
Net income per share – basic (in dollars per share)	$ 2.63	$ 1.40
Weighted-average shares – basic (in shares)	25,377,000	27,858,000
Diluted net income per share:
Net income per share – diluted (in dollars per share)	$ 2.51	$ 1.36
Weighted-average shares – diluted (in shares)	26,544,000	28,772,000