Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 1,378	$ (1,937)	$ 3,269	$ (21,304)
Foreign currency translation adjustments, net of zero tax	(4,687)	(2,281)	(4,098)	(3,118)
Defined benefit pension plans adjustment, net of tax of $73				118
Unrealized gains (losses) on available-for-sale securities, net of zero tax	(1)		(5)	3
Comprehensive loss	$ (3,310)	$ (4,218)	$ (834)	$ (24,301)