Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 22,758	$ 22,854	$ 57,713	$ 65,316
Europe
Disaggregation of Revenue [Line Items]
Revenue	9,681	7,552	25,614	26,239
Latin America
Disaggregation of Revenue [Line Items]
Revenue	5,207	9,406	13,715	21,590
Asia-Pacific/Middle East
Disaggregation of Revenue [Line Items]
Revenue	7,692	5,851	18,042	17,073
Other
Disaggregation of Revenue [Line Items]
Revenue	$ 178	$ 45	$ 342	$ 414