Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 25, 2020	Oct. 26, 2019	Jul. 27, 2019	Apr. 27, 2019	Jan. 26, 2019	Oct. 27, 2018	Jul. 28, 2018	Apr. 28, 2018	Jan. 25, 2020	Jan. 26, 2019	Jan. 27, 2018
Net sales	$ 397,716	$ 318,734	$ 342,321	$ 306,264	$ 354,065	$ 267,180	$ 288,493	$ 256,161	$ 1,365,035	$ 1,165,899	$ 950,528
Gross profit	114,091	85,413	100,398	88,051	117,239	85,991	97,378	85,244	387,952	385,851	306,958
Operating income (loss)	(209,149)	1,986	21,813	25,889	44,568	19,096	(11,828)	24,200	(159,462)	76,035	87,361
Net income (loss)	$ (224,053)	$ (14,647)	$ 10,382	$ 13,883	$ 29,613	$ 11,090	$ (10,068)	$ 18,361	$ (214,435)	$ 48,996	$ 31,812
Basic net income (loss) per common share	$ (3.50)	$ (0.23)	$ 0.16	$ 0.22	$ 0.47	$ 0.17	$ (0.16)	$ 0.30	$ (3.35)	$ 0.78	$ 0.53
Diluted net income (loss) per common share	$ (3.50)	$ (0.23)	$ 0.16	$ 0.21	$ 0.45	$ 0.17	$ (0.16)	$ 0.28	$ (3.35)	$ 0.74	$ 0.50
Goodwill, Impairment Loss	$ 250,000								$ 250,000	$ 0	$ 0
Stock-based compensation expense									$ 7,400	$ 49,500	$ 13,800
Chairman and Chief Executive Officer
Stock-based compensation expense							$ 41,500