Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Commitments [Line Items]
Rent expense	$ 14,500	$ 13,600	$ 11,400
Deferred credits	2,300	2,400
Property, plant, and equipment grants from Ireland	142	147	170
Royalty expense	$ 5,300	$ 4,400	$ 3,200
Minimum
Other Commitments [Line Items]
Grant period	5 years
Maximum
Other Commitments [Line Items]
Grant period	8 years