Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Operating lease cost	$ 1,392	$ 1,347	$ 2,774	$ 2,727
Short-term lease cost	2,037	2,232	4,014	4,169
Short-term lease cost - related party	899	920	1,789	1,822
Total lease cost	4,328	$ 4,499	$ 8,577	$ 8,718
Cash paid for amounts included in the measurement of lease liabilities - operating leases	$ 1,362
Weighted-average remaining lease term - operating leases	5 years 3 months 18 days		5 years 3 months 18 days
Weighted-average discount rate - operating leases	5.33%		5.33%