Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Revenue, Current
Total Deferred Revenue, Current	$ 182	$ 5,554
Deferred Revenue, Non-Current
Deferred revenue, non-current		2,636
Total Deferred Revenue	182	8,190
Maintenance Agreements [Member]
Deferred Revenue, Current
Total Deferred Revenue, Current	89	5,554
Deferred Revenue, Non-Current
Deferred revenue, non-current		2,636
Service and Other Agreements [Member]
Deferred Revenue, Current
Total Deferred Revenue, Current	$ 93