Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Cash equivalents
Carrying Value	$ 56,750	$ 5,563
Short-term investments
Amortized Cost	71,308	81,291
Unrealized Gains	191	58
Unrealized Losses	0	(4)
Aggregate Fair Value	71,499	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	128,058	88,132
Total marketable securities, Unrealized Gains	191	58
Total marketable securities, Unrealized Losses	0	(4)
Total marketable securities, Aggregate Fair Value	128,249	88,186
Money market funds
Cash equivalents
Carrying Value	56,750	3,068
U.S. treasury securities
Short-term investments
Amortized Cost	60,010	67,051
Unrealized Gains	133	34
Unrealized Losses	0	(2)
Aggregate Fair Value	60,143	67,083
Corporate bonds
Short-term investments
Amortized Cost	8,604	9,075
Unrealized Gains	58	24
Unrealized Losses	0	(2)
Aggregate Fair Value	8,662	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		2,495
Short-term investments
Amortized Cost	2,694	5,165
Unrealized Gains	0	0
Unrealized Losses	0	0
Aggregate Fair Value	$ 2,694	$ 5,165