Leases - Components of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Sublease income	$ (25)	$ (75)
Operating lease cost	156	474
Operating lease cost, net	131	399
Sublease income	(111)	(334)
Lease cost	105	321
Restructured lease cost, net	(6)	(13)
Interest on lease liabilities	1	2
Total lease cost, net	$ 126	$ 388