Segment Reporting and Significant Customer Information - Operating Results from Continuing Operations and Assets by Business Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Summary of operating results from continuing operations and assets by business segment
Revenues	$ 33,728	$ 36,307	$ 109,665	$ 118,949
Operating income (loss)	860	1,846	6,170	17,614
North America
Summary of operating results from continuing operations and assets by business segment
Revenues	20,693	22,922	69,448	74,907
Operating income (loss)	687	265	5,322	8,718
Europe
Summary of operating results from continuing operations and assets by business segment
Revenues	10,317	10,595	32,138	35,745
Operating income (loss)	587	195	2,363	5,470
Asia Pacific
Summary of operating results from continuing operations and assets by business segment
Revenues	2,718	2,790	8,079	8,297
Operating income (loss)	(414)	(864)	(1,515)	(2,324)
Operating Segments | North America
Summary of operating results from continuing operations and assets by business segment
Revenues	20,538	22,601	68,978	74,130
Operating Segments | Europe
Summary of operating results from continuing operations and assets by business segment
Revenues	10,444	10,899	32,560	36,451
Operating Segments | Asia Pacific
Summary of operating results from continuing operations and assets by business segment
Revenues	2,746	2,807	8,127	8,368
Elimination
Summary of operating results from continuing operations and assets by business segment
Revenues	0	0	0	0
Operating income (loss)	0	2,250	0	5,750
Elimination | North America
Summary of operating results from continuing operations and assets by business segment
Revenues	155	321	470	777
Elimination | Europe
Summary of operating results from continuing operations and assets by business segment
Revenues	(127)	(304)	(422)	(706)
Elimination | Asia Pacific
Summary of operating results from continuing operations and assets by business segment
Revenues	$ (28)	$ (17)	$ (48)	$ (71)