Income Taxes - Components of Income Tax (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jan. 27, 2018	Jan. 28, 2017	Jan. 25, 2020	Jan. 26, 2019	Jul. 29, 2017
Current:
Federal	$ (4,384)		$ 8,389	$ 9,507	$ 62,455
Foreign	598		(56)	2,204	176
State	1,166		3,727	4,897	12,344
Current Income Tax Expense (Benefit)	(2,620)		12,060	16,608	74,975
Deferred:
Federal	(21,332)		7,257	8,706	17,051
Foreign	(37)		568	(446)	(35)
State	1,704		1,436	263	1,217
Deferred income tax (benefit) provision	(19,665)		9,261	8,523	18,233
Total provision for income taxes	$ (22,285)	$ 44,332	$ 21,321	$ 25,131	$ 93,208