Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Right-of-use assets	$ 3,088	$ 3,379
Italian VAT receivables, net	0	4,390
Italian VAT deposit, net	0	483
Clinical trial deposits	720	720
Refundable security deposit	194	194
Other	238	299
Other assets	$ 4,240	$ 9,465