Leases - Summary of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Finance lease cost:
Amortization of right-of-use asset	$ 45	$ 60
Interest expense on lease liability	35	46
Total finance lease cost	80	106
Operating lease cost	515	1,030
Sublease income	(7)	(12)
Total lease costs	$ 588	$ 1,124