Leasing Arrangements - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Lessee, Lease, Description [Line Items]
Lease cost	$ 1,634		$ 4,918
Operating lease, rent expense		$ 1,600		$ 4,900
Selling, General and Administrative Expenses
Lessee, Lease, Description [Line Items]
Lease cost	800		2,600
Cost of Sales
Lessee, Lease, Description [Line Items]
Lease cost	400		1,200
Research and Development Expense
Lessee, Lease, Description [Line Items]
Lease cost	$ 400		$ 1,100