Business Segment, Geographic, and Concentration Risk Information - Summary of Revenue by Geographical Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Total revenue:
Total consolidated revenue	$ 4,595	$ 5,193	$ 9,176	$ 9,822
United States
Total revenue:
Total consolidated revenue	2,227	1,011	2,940	1,513
India
Total revenue:
Total consolidated revenue	790	1,252	2,261	3,208
Austria
Total revenue:
Total consolidated revenue	716	1,792	1,718	3,184
China
Total revenue:
Total consolidated revenue	417	655	729	1,111
Taiwan
Total revenue:
Total consolidated revenue	0	0	500	0
Other Foreign Countries
Total revenue:
Total consolidated revenue	$ 445	$ 483	$ 1,028	$ 806