Common Stock and Stock-Based Compensation - Options Activity (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2021 $ / shares shares
Shares (in thousands)
Options outstanding, beginning of period (in shares) | shares	5,311
Granted (in shares) | shares	1,625
Exercised (in shares) | shares	(50)
Canceled (in shares) | shares	(330)
Options outstanding, end of period (in shares) | shares	6,556
Weighted- Average Exercise Price per Share
Outstanding weighted average exercise price, beginning balance (in usd per share) | $ / shares	$ 29.12
Granted weighted average exercise price (in usd per share) | $ / shares	18.21
Exercised weighted average exercise price (in usd per share) | $ / shares	9.77
Canceled weighted average exercise price (in usd per share) | $ / shares	28.73
Outstanding weighted average exercise price, ending balance (in usd per share) | $ / shares	$ 26.58