Leases - Components of lease costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Operating and finance lease costs
Amortization of right-of-use assets	$ 7,601
Interest expense	877
Operating lease cost	8,329
Short-term lease cost	847
Variable lease cost	528
Sublease income	(455)
Total lease cost	$ 17,727