Business Segment, Geographic and Major Customer Information - Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues from External Customers and Long-Lived Assets
Revenue	$ 9,165	$ 8,880	$ 20,935	$ 28,296
U.S.
Revenues from External Customers and Long-Lived Assets
Revenue	6,869	6,936	16,530	22,711
UAE
Revenues from External Customers and Long-Lived Assets
Revenue	1,319	847	2,422	2,308
Other countries
Revenues from External Customers and Long-Lived Assets
Revenue	$ 977	$ 1,097	$ 1,983	$ 3,277