Leases - Summary of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Total lease cost	$ 2,946	$ 5,495
Short-term lease cost		1,489
Cost of revenue
Lessee, Lease, Description [Line Items]
Total lease cost	2,091	3,785
Operating expenses
Lessee, Lease, Description [Line Items]
Total lease cost	$ 855	$ 1,710