Leases - Maturity of lease payments (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Leases
2020	$ 2,611
2021	1,997
2022	1,096
2023	949
-Thereafter	3,851
Total undiscounted operating lease payments	10,504
Less imputed interest	(2,398)
Present value of operating lease liabilities	$ 8,106
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesAndOtherLiabilities us-gaap:OperatingLeaseLiabilityNoncurrent