Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash equivalents
Carrying Value	$ 47,348	$ 5,563
Short-term investments
Amortized Cost	142,856	81,291
Unrealized Gains	8	58
Unrealized Losses	(13)	(4)
Aggregate Fair Value	142,851	81,345
Long-term investments
Amortized Cost		1,278
Unrealized Gains		0
Unrealized Losses		0
Aggregate Fair Value	0	1,278
Total marketable securities, Amortized Cost	190,204	88,132
Total marketable securities, Unrealized Gains	8	58
Total marketable securities, Unrealized Losses	(13)	(4)
Total marketable securities, Aggregate Fair Value	190,199	88,186
Money market funds
Cash equivalents
Carrying Value	45,948	3,068
U.S. treasury securities
Short-term investments
Amortized Cost	74,779	67,051
Unrealized Gains	4	34
Unrealized Losses	(7)	(2)
Aggregate Fair Value	74,776	67,083
Corporate bonds
Short-term investments
Amortized Cost	8,940	9,075
Unrealized Gains	4	24
Unrealized Losses	(6)	(2)
Aggregate Fair Value	8,938	9,097
Long-term investments
Amortized Cost		1,278
Unrealized Gains		0
Unrealized Losses		0
Aggregate Fair Value		1,278
Commercial paper
Cash equivalents
Carrying Value	1,400	2,495
Short-term investments
Amortized Cost	59,137	5,165
Unrealized Gains	0	0
Unrealized Losses	0	0
Aggregate Fair Value	$ 59,137	$ 5,165