Leases – Components of lease expense and other information (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Lease cost
Amortization of right-of-use assets	$ 337	$ 1,038
Interest on lease liabilities	126	235
Operating lease cost	3,293	5,164
Variable lease cost	208	395
Short-term lease cost	29	48
Total lease cost	$ 3,993	$ 6,880
Weighted-average remaining lease term (years), Operating leases	5 years 2 months 1 day	5 years 2 months 1 day
Weighted-average remaining lease term (years), Finance leases	2 years 6 months 15 days	2 years 6 months 15 days
Weighted-average discount rate, Operating leases	5.20%	5.20%
Weighted-average discount rate, Finance leases	5.50%	5.50%