Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Company’s assets that were accounted for at fair value on a recurring basis
Short-term investments	$ 10,016	$ 24,962
Recurring
Company’s assets that were accounted for at fair value on a recurring basis
Total	19,054	38,911
Recurring | Level 1
Company’s assets that were accounted for at fair value on a recurring basis
Total	19,054	38,911
Recurring | Money market funds
Company’s assets that were accounted for at fair value on a recurring basis
Cash equivalents	9,038	13,949
Recurring | Money market funds | Level 1
Company’s assets that were accounted for at fair value on a recurring basis
Cash equivalents	9,038	13,949
Recurring | U.S. Treasury securities
Company’s assets that were accounted for at fair value on a recurring basis
Short-term investments	10,016	24,962
Recurring | U.S. Treasury securities | Level 1
Company’s assets that were accounted for at fair value on a recurring basis
Short-term investments	$ 10,016	$ 24,962