Earnings Per Share (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
Numerator:
Net (loss) income	$ (224,053)	$ (14,647)	$ 10,382	$ 13,883	$ 29,613	$ 11,090	$ (10,068)	$ 18,361	$ (214,435)	$ 48,996	$ 31,812
Denominator:
Weighted average common shares outstanding-basic									63,975,633	62,936,959	60,503,860
Effect of dilutive securities:
Stock options and restricted stock units										3,362,687	3,208,143
Weighted average common shares outstanding-diluted									63,975,633	66,299,646	63,712,003
Net (loss) income per common share:
Basic	$ (3.50)	$ (0.23)	$ 0.16	$ 0.22	$ 0.47	$ 0.17	$ (0.16)	$ 0.30	$ (3.35)	$ 0.78	$ 0.53
Diluted	$ (3.50)	$ (0.23)	$ 0.16	$ 0.21	$ 0.45	$ 0.17	$ (0.16)	$ 0.28	$ (3.35)	$ 0.74	$ 0.50