Stock-Based Compensation and Employee Benefit Plans - Number of Shares Available for Grant (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Options/ RSUs Available for Grant
Beginning balance (in shares)	17,457,847	1,037,616
Added to plan (in shares)	7,585,422	40,924,861
Granted (in shares)	(8,176,023)	(18,075,790)
Cancelled (in shares)	2,289,290	1,061,054
Expired (in shares)	(1,923,392)	(7,489,894)
Ending Balance (in shares)	17,233,144	17,457,847