Revenues - Disaggregation of Revenues by Revenue Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue from External Customer [Line Items]
Revenues	$ 213,699	$ 228,805	$ 643,006	$ 648,735
Product revenues
Revenue from External Customer [Line Items]
Revenues	151,337	168,488	460,352	472,477
Hardware and software
Revenue from External Customer [Line Items]
Revenues	130,046	142,424	389,398	394,243
Consumables
Revenue from External Customer [Line Items]
Revenues	16,840	22,204	58,173	67,706
Other
Revenue from External Customer [Line Items]
Revenues	$ 4,451	$ 3,860	$ 12,781	$ 10,528