Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Cash equivalents
Carrying Value	$ 54,218	$ 47,348
Short-term investments
Amortized Cost	100,988	142,856
Unrealized Gains	3	8
Unrealized Losses	(3)	(13)
Aggregate Fair Value	100,988	142,851
Total marketable securities, Amortized Cost	155,206	190,204
Total marketable securities, Unrealized Gains	3	8
Total marketable securities, Unrealized Losses	(3)	(13)
Total marketable securities, Aggregate Fair Value	155,206	190,199
Money market funds
Cash equivalents
Carrying Value	54,218	45,948
U.S. treasury securities
Short-term investments
Amortized Cost	52,140	74,779
Unrealized Gains	3	4
Unrealized Losses	0	(7)
Aggregate Fair Value	52,143	74,776
Corporate bonds
Short-term investments
Amortized Cost	15,373	8,940
Unrealized Gains	0	4
Unrealized Losses	(3)	(6)
Aggregate Fair Value	15,370	8,938
Commercial paper
Cash equivalents
Carrying Value		1,400
Short-term investments
Amortized Cost	33,475	59,137
Unrealized Gains	0	0
Unrealized Losses	0	0
Aggregate Fair Value	$ 33,475	$ 59,137