Commitments and Contingencies - Lease liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Operating Leases
2020 (April 1 - December 31)	$ 1,017
2021	1,376
2022	1,401
2023	1,425
2024	1,450
2025 and beyond	5,136
Total minimum lease payments	11,805
Interest Expense	(3,546)
Lease Liability	8,259	$ 8,404
Financing Leases
2020 (April 1 - December 31)	8
2021	8
2022	4
Total minimum lease payments	20
Interest Expense	(2)
Lease Liability	18
Sublease
2020 (April 1 - December 31)	809
2021	943
Total minimum lease payments	$ 1,752