Revenues - Disaggregation of Revenues by Revenue Type (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 897,027	$ 787,309	$ 712,714
Product [Member]
Disaggregation of Revenue [Line Items]
Revenues	659,602	569,595	510,201
Hardware and software
Disaggregation of Revenue [Line Items]
Revenues	553,039	464,500	406,095
Consumables
Disaggregation of Revenue [Line Items]
Revenues	88,876	89,529	88,100
Other
Disaggregation of Revenue [Line Items]
Revenues	$ 17,687	$ 15,566	$ 16,006