Segment Reporting and Significant Customer Information - Assets by Segment (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Revenue for each segment recognized based on customer location
Long-lived assets	$ 5,265	$ 6,158
Total assets	43,164	53,530
Elimination
Revenue for each segment recognized based on customer location
Long-lived assets	0	0
Total assets	(70,520)	(66,851)
Asia Pacific | Operating Segments
Revenue for each segment recognized based on customer location
Long-lived assets	151	209
Total assets	3,490	5,295
Europe | Operating Segments
Revenue for each segment recognized based on customer location
Long-lived assets	577	763
Total assets	49,721	49,125
North America | Operating Segments
Revenue for each segment recognized based on customer location
Long-lived assets	4,537	5,186
Total assets	$ 60,473	$ 65,961