Business Segment, Geographic and Major Customer Information - Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets
Revenue	$ 12,739	$ 21,879	$ 41,035	$ 99,827
U.S.
Revenues from External Customers and Long-Lived Assets
Revenue	9,928	19,663	32,639	89,653
U.A.E
Revenues from External Customers and Long-Lived Assets
Revenue	1,473	865	3,781	2,662
Other countries
Revenues from External Customers and Long-Lived Assets
Revenue	$ 1,338	$ 1,351	$ 4,615	$ 7,512