Net Loss Per Share - Anti-dilutive common equivalent shares (Details) - shares	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Net Loss Per Share
Total anti-dilutive common equivalent shares	48,851,417	41,343,105
Stock options
Net Loss Per Share
Total anti-dilutive common equivalent shares	15,544,806	17,351,206
Restricted stock units
Net Loss Per Share
Total anti-dilutive common equivalent shares	12,653,874	3,338,871
Outstanding warrants
Net Loss Per Share
Total anti-dilutive common equivalent shares	20,652,737	20,653,028