Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 3,339	$ 3,510	$ 10,443	$ 10,269
Finance lease cost:
Amortization of ROU assets	2,311	2,311	6,933	7,096
Interest on lease liabilities	416	271	1,323	1,256
Other lease costs and income:
Variable lease costs	2,601	2,318	7,443	7,185
Operating lease ROU asset impairment charges	6,392	0	6,392	0
Sublease income	(1,077)	(932)	(2,870)	(2,828)
Cost of revenues
Lessee, Lease, Description [Line Items]
Lease, cost	2,815	2,793	8,589	8,425
Selling, general and administrative
Lessee, Lease, Description [Line Items]
Lease, cost	4,309	4,347	13,209	13,145
Research and development
Lessee, Lease, Description [Line Items]
Lease, cost	$ 50	$ 67	$ 151	$ 152