Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 3,510	$ 10,269
Finance lease cost:
Amortization of ROU assets	2,311	7,096
Interest on lease liabilities	271	1,256
Other lease costs and income:
Variable lease costs	2,318	7,185
Sublease income	(932)	(2,828)
Cost of revenues
Lessee, Lease, Description [Line Items]
Lease, cost	2,793	8,425
Selling, general and administrative expenses
Lessee, Lease, Description [Line Items]
Lease, cost	4,347	13,145
Research and development expenses
Lessee, Lease, Description [Line Items]
Lease, cost	$ 67	$ 152