Business Segment, Geographic and Major Customer Information - Geographic Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue by geographic location
Revenue	$ 53,141	$ 119,353
U.S.
Revenue by geographic location
Revenue	40,632	104,786
UAE
Revenue by geographic location
Revenue	6,763	3,897
Other countries
Revenue by geographic location
Revenue	$ 5,746	$ 10,670