Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Cash equivalents
Carrying Value	$ 52,290	$ 5,563
Short-term investments
Amortized Cost	75,981	81,291
Unrealized Gains	43	58
Unrealized Losses	0	(4)
Aggregate Fair Value	76,024	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	128,271	88,132
Total marketable securities, Unrealized Gains	43	58
Total marketable securities, Unrealized Losses	0	(4)
Total marketable securities, Aggregate Fair Value	128,314	88,186
Money market funds
Cash equivalents
Carrying Value	52,290	3,068
U.S. treasury securities
Short-term investments
Amortized Cost	56,994	67,051
Unrealized Gains	24	34
Unrealized Losses	0	(2)
Aggregate Fair Value	57,018	67,083
Corporate bonds
Short-term investments
Amortized Cost	8,595	9,075
Unrealized Gains	19	24
Unrealized Losses	0	(2)
Aggregate Fair Value	8,614	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	10,392	5,165
Unrealized Gains	0	0
Unrealized Losses	0	0
Aggregate Fair Value	$ 10,392	$ 5,165