Stock-Based Compensation - Restricted Stock Units (Details) - Restricted stock units that settle into Class A common stock - Class A common stock	12 Months Ended
	Jul. 31, 2021 $ / shares shares
Class A Common Stock
Unvested, beginning balance (in shares) | shares	9,123,341
Granted (in shares) | shares	6,463,980
Vested (in shares) | shares	(2,132,298)
Forfeited (in shares) | shares	(3,190,098)
Unvested, ending balance (in shares) | shares	10,264,925
Weighted- Average Grant Date Fair Value
Unvested, beginning balance (in dollars per share) | $ / shares	$ 20.11
Granted (in dollars per share) | $ / shares	40.33
Vested (in dollars per share) | $ / shares	21.62
Forfeited (in dollars per share) | $ / shares	23.83
Unvested, ending balance (in dollars per share) | $ / shares	$ 31.35