Segment Reporting and Significant Customer Information - Operating Results from Continuing Operations and Assets by Business Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Summary of operating results from continuing operations and assets by business segment
Revenues	$ 34,804	$ 39,145
Operating income (loss)	3,148	2,982
Asia Pacific
Summary of operating results from continuing operations and assets by business segment
Revenues	2,260	2,648
Operating income (loss)	(1,044)	(833)
Europe
Summary of operating results from continuing operations and assets by business segment
Revenues	10,892	11,562
Operating income (loss)	2,094	1,729
North America
Summary of operating results from continuing operations and assets by business segment
Revenues	21,652	24,935
Operating income (loss)	2,098	2,086
Operating Segments | Asia Pacific
Summary of operating results from continuing operations and assets by business segment
Revenues	2,259	2,653
Operating Segments | Europe
Summary of operating results from continuing operations and assets by business segment
Revenues	10,966	11,779
Operating Segments | North America
Summary of operating results from continuing operations and assets by business segment
Revenues	21,579	24,713
Other
Summary of operating results from continuing operations and assets by business segment
Revenues	0	0
Operating income (loss)	0	0
Other | Asia Pacific
Summary of operating results from continuing operations and assets by business segment
Revenues	1	(5)
Other | Europe
Summary of operating results from continuing operations and assets by business segment
Revenues	(74)	(217)
Other | North America
Summary of operating results from continuing operations and assets by business segment
Revenues	$ 73	$ 222