Stock-Based Compensation and Employee Benefit Plan - Number of Shares Available for Grant (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Options/ RSUs Available for Grant
Beginning balance (in shares)	17,233,144	17,457,847
Added to plan (in shares)	7,179,751	7,585,422
Granted (in shares)	(4,944,467)	(8,176,023)
Cancelled (in shares)	1,965,801	2,289,290
Expired (in shares)	(1,200,475)	(1,923,392)
Ending Balance (in shares)	20,233,754	17,233,144