Income Taxes - Federal Statutory Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 25, 2020	Jan. 26, 2019	Jan. 27, 2018
Reconciliation between the actual income tax provision (benefit) and income tax provision (benefit) calculated at federal statutory tax rate:
Income tax provision at the federal statutory rate	$ (40,165)	$ 10,286	$ 22,297
Permanent differences	399	340	325
Impairment charges	52,500
State income taxes, net of federal income tax effect	1,843	(112)	596
Change in unrecognized tax benefits	(249)	(495)	(130)
Change in valuation allowance			(314)
Effect of the Tax Act		(524)	16,694
Equity-based compensation	9,115	(9,293)	(5,826)
Tax credits	(319)	(278)	(208)
Deferred adjustment	48	59	411
Income tax provision (benefit)	$ 23,172	$ (17)	$ 33,845
Effective tax rate (as a percent)	(12.10%)	0.00%	51.50%