Leases - Components of Lease Expense (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 3,499
Finance lease cost:
Amortization of ROU assets	2,296
Interest on lease liabilities	500
Other lease costs and income:
Variable lease costs	2,089
Sublease income	(964)
Cost of revenues
Lessee, Lease, Description [Line Items]
Lease, cost	2,700
Selling, general and administrative expenses
Lessee, Lease, Description [Line Items]
Lease, cost	4,100
Research and development expenses
Lessee, Lease, Description [Line Items]
Lease, cost	$ 100