Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Net Loss Per Share
Net loss (numerator)	$ (50,486)	$ (53,515)	$ (52,796)	$ (41,805)	$ (37,672)	$ (31,472)	$ (156,797)	$ (110,949)
Weighted average shares (denominator) - basic (in shares)	29,268			28,022			29,026	27,997
Weighted average shares (denominator) - diluted (in shares)	29,268			28,022			29,026	27,997
Basic net loss per share (in dollars per share)	$ (1.72)			$ (1.49)			$ (5.40)	$ (3.96)
Diluted net loss per share (in dollars per share)	$ (1.72)			$ (1.49)			$ (5.40)	$ (3.96)
Common stock equivalents outstanding							5,688	4,986