Revenue Recognition - Contracts With Customers Excludes Leasing (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Revenues	$ 99,735		$ 277,454
Western Hemisphere | Operating Segments
Disaggregation Of Revenue [Line Items]
Revenues	53,618		147,883
Eastern Hemisphere | Operating Segments
Disaggregation Of Revenue [Line Items]
Revenues	28,310		81,343
Asia Pacific | Operating Segments
Disaggregation Of Revenue [Line Items]
Revenues	17,807		48,228
Products
Disaggregation Of Revenue [Line Items]
Revenues	81,851	$ 63,246	224,518	$ 199,010
Products | Western Hemisphere | Operating Segments
Disaggregation Of Revenue [Line Items]
Revenues	42,561		117,820
Products | Eastern Hemisphere | Operating Segments
Disaggregation Of Revenue [Line Items]
Revenues	23,656		66,815
Products | Asia Pacific | Operating Segments
Disaggregation Of Revenue [Line Items]
Revenues	15,634		39,883
Services
Disaggregation Of Revenue [Line Items]
Revenues	17,884		52,936
Services | Western Hemisphere | Operating Segments
Disaggregation Of Revenue [Line Items]
Revenues	11,057		30,063
Services | Eastern Hemisphere | Operating Segments
Disaggregation Of Revenue [Line Items]
Revenues	4,654		14,528
Services | Asia Pacific | Operating Segments
Disaggregation Of Revenue [Line Items]
Revenues	$ 2,173		$ 8,345