Revenue From Contracts With Customers - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Net revenues	$ 41,775	$ 24,743	$ 78,731	$ 58,251
Latin America
Disaggregation of Revenue [Line Items]
Net revenues	14,321	7,594	27,852	17,446
North America
Disaggregation of Revenue [Line Items]
Net revenues	13,645	4,309	20,802	12,357
Europe
Disaggregation of Revenue [Line Items]
Net revenues	6,123	6,060	16,515	11,609
Asia Pacific
Disaggregation of Revenue [Line Items]
Net revenues	3,676	3,929	5,543	7,863
Africa
Disaggregation of Revenue [Line Items]
Net revenues	2,278	2,222	4,667	7,241
Middle East
Disaggregation of Revenue [Line Items]
Net revenues	1,106	441	2,465	1,190
Commonwealth of Independent States
Disaggregation of Revenue [Line Items]
Net revenues	$ 626	$ 188	$ 887	$ 545