Revenue Recognition (Adoption of ASC 606) - Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 80,787	$ 252,013
Products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	63,246	199,010
Services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	17,541	53,003
Intercompany
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Intercompany | Products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Intercompany | Services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Western Hemisphere | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	53,994	159,432
Western Hemisphere | Operating Segments | Products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	43,825	130,259
Western Hemisphere | Operating Segments | Services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10,169	29,173
Eastern Hemisphere | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	22,198	67,723
Eastern Hemisphere | Operating Segments | Products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	17,834	52,238
Eastern Hemisphere | Operating Segments | Services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	4,364	15,485
Asia-Pacific | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	4,595	24,858
Asia-Pacific | Operating Segments | Products
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,587	16,513
Asia-Pacific | Operating Segments | Services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 3,008	$ 8,345