CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Statement of Comprehensive Income [Abstract]
Net sales	$ 803,429	$ 645,289	$ 1,563,737	$ 1,251,560
Cost of sales	549,678	446,569	1,072,960	865,823
Gross profit	253,751	198,720	490,777	385,737
Operating expenses:
Selling, general and administrative	198,002	157,641	384,933	310,495
Depreciation and amortization	13,215	12,594	26,160	24,890
Share-based compensation	10,175	22,750	30,452	22,961
Total operating expenses	221,392	192,985	441,545	358,346
Income from operations	32,359	5,735	49,232	27,391
Other expenses:
Interest expense, net	5,270	15,452	11,104	31,890
Debt extinguishment and modification costs	0	5,162	198	5,162
Total other expenses	5,270	20,614	11,302	37,052
Income (loss) before income taxes	27,089	(14,879)	37,930	(9,661)
Income tax benefit	(2,244)	(4,247)	(4,045)	(2,803)
Net Income (loss)	29,333	(10,632)	41,975	(6,858)
Comprehensive income (loss)	$ 29,333	$ (10,632)	$ 41,975	$ (6,858)
Basic earnings (loss) per share (in usd per share)	$ 0.32	$ (0.15)	$ 0.47	$ (0.10)
Diluted earnings (loss) per share (in usd per share)	$ 0.30	$ (0.15)	$ 0.43	$ (0.10)
Weighted average shares outstanding:
Basic (in shares)	90,800	70,475	90,152	69,494
Diluted (in shares)	98,618	70,475	97,333	69,494