Stock-Based Compensation and Employee Benefit Plan - Number of Shares Available for Grant (Details)	9 Months Ended
	Sep. 30, 2020 shares
Options/ RSUs Available for Grant
Beginning balance (in shares)	17,233,144
Added to plan (in shares)	6,928,556
Granted (in shares)	(4,621,528)
Cancelled (in shares)	1,396,524
Expired (in shares)	(949,280)
Ending Balance (in shares)	19,987,416