Leases - Summary of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Total lease cost	$ 2,894	$ 8,389
Short-term lease cost	399	1,889
Cost of revenue
Lessee, Lease, Description [Line Items]
Total lease cost	2,029	5,814
Operating expenses
Lessee, Lease, Description [Line Items]
Total lease cost	$ 865	$ 2,575