Leases - Lease Cost (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($) lease_arrangement
Lessee, Lease, Description [Line Items]
Number of lease arrangements | lease_arrangement		9
Operating lease cost	$ 171	$ 514
Short-term lease cost	1	135
Total lease cost	$ 172	$ 649
Weighted average remaining lease term	4 years 4 months	4 years 4 months
Weighted average discount rate	3.52%	3.52%
Minimum
Lessee, Lease, Description [Line Items]
Term of lease	1 year	1 year
Maximum
Lessee, Lease, Description [Line Items]
Term of lease	6 years	6 years