Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2021	Sep. 26, 2020	Oct. 02, 2021	Sep. 26, 2020
Income Statement [Abstract]
Net sales	$ 640,393	$ 531,155	$ 1,692,965	$ 1,288,659
Cost of sales	250,039	196,195	653,842	488,558
Gross profit	390,354	334,960	1,039,123	800,101
Operating expenses:
Sales and marketing	255,512	211,574	685,123	549,483
General and administrative	47,676	44,127	131,488	111,915
Research and development	14,431	9,644	43,633	28,399
Total operating expenses	317,619	265,345	860,244	689,797
Operating income	72,735	69,615	178,879	110,304
Interest expense, net	1,816	1,827	4,400	8,111
Income before income taxes	70,919	67,788	174,479	102,193
Income tax expense	17,198	16,468	31,874	24,363
Net income	$ 53,721	$ 51,320	$ 142,605	$ 77,830
Basic net income per share:
Net income per share – basic (in dollars per share)	$ 2.29	$ 1.83	$ 5.84	$ 2.79
Weighted-average shares – basic (in shares)	23,464,000	27,973,000	24,404,000	27,918,000
Diluted net income per share:
Net income per share – diluted (in dollars per share)	$ 2.22	$ 1.79	$ 5.63	$ 2.73
Weighted-average shares – diluted (in shares)	24,233,000	28,634,000	25,324,000	28,560,000