Commitments and Contingencies - Lease Expense (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Finance lease costs
Amortization of right-of-use assets	$ 22
Interest on lease liabilities	4
Operating lease costs	1,910
Short term lease costs	41
Variable lease costs	17
Total lease cost	$ 1,994