Leases - Components of lease cost (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Lease cost:
Operating lease cost	$ 1,285
Short-term lease cost	166
Total lease cost	1,451
Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases	$ 1,331
Weighted average remaining lease term- operating leases	5 years 3 months 18 days
Weighted average discount rate- operating leases	3.00%