Fair Value - Schedule of Fair Value of Financial Instruments Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Money market funds	$ 19,065	$ 2,019
Commercial paper	747	11,064
Corporate debt securities	997	8,982
U.S. government debt securities		3,770
Total	20,809	25,835
Common stock warrant liability	7,145
Contingent consideration		31
Total	7,145	31
Level 1 [Member]
Money market funds	19,065	2,019
Commercial paper
Corporate debt securities
U.S. government debt securities
Total	19,065	2,019
Common stock warrant liability
Contingent consideration
Total
Level 2 [Member]
Money market funds
Commercial paper	747	11,064
Corporate debt securities	997	8,982
U.S. government debt securities		3,770
Total	1,744	23,816
Common stock warrant liability
Contingent consideration
Total
Level 3 [Member]
Money market funds
Commercial paper
Corporate debt securities
U.S. government debt securities
Total
Common stock warrant liability	7,145
Contingent consideration		31
Total	$ 7,145	$ 31