Income Taxes - Components of Net Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2021	Aug. 01, 2020	Aug. 03, 2019
Income Tax Disclosure [Abstract]
United States	$ (62,341)	$ (48,302)	$ 31,657
Foreign	1,224	580	(836)
Income (loss) before income taxes	$ (61,117)	$ (47,722)	$ 30,821