Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating lease cost	$ 1,406	$ 2,807
Finance lease cost
Amortization of ROU asset	45	69
Interest expense	14	21
Short-term lease cost	133	276
Variable lease cost	311	766
Total lease cost	$ 1,909	$ 3,939