Earnings (Loss) Per Share Attributable to Common Stockholders - Common Stock Equivalents Excluded From Computation of Diluted Earnings (Loss) Per Share (Details) - shares	12 Months Ended
	Jul. 31, 2021	Aug. 01, 2020	Aug. 03, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock equivalents excluded from the computation of diluted earnings (loss) per share (in shares)	13,915,407	14,430,373	5,431,304
Restricted stock units that settle into Class A common stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock equivalents excluded from the computation of diluted earnings (loss) per share (in shares)	10,264,925	7,965,447	2,914,630
Class A common stock | Options
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock equivalents excluded from the computation of diluted earnings (loss) per share (in shares)	2,361,055	2,924,512	1,547,495
Class B common stock | Options
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock equivalents excluded from the computation of diluted earnings (loss) per share (in shares)	1,289,427	3,540,414	969,179