Revenues - Disaggregation of Revenues by Revenue Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue from External Customer [Line Items]
Revenues	$ 199,621	$ 217,413	$ 429,307	$ 419,930
Product revenues
Revenue from External Customer [Line Items]
Revenues	138,942	158,379	309,015	303,989
Hardware and software
Revenue from External Customer [Line Items]
Revenues	116,919	133,005	259,352	251,819
Consumables
Revenue from External Customer [Line Items]
Revenues	18,063	21,795	41,333	45,502
Other
Revenue from External Customer [Line Items]
Revenues	$ 3,960	$ 3,579	$ 8,330	$ 6,668