Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 2,522	$ 145	$ 475	$ (1,101)
Other comprehensive income (loss):
Foreign currency translation adjustments	4,675	(2,840)	8,933	899
Retirement plans related adjustments	(527)	1,575	(251)	1,302
Unrealized (loss) gain on cash flow hedges	(299)	(33)	(68)	132
Other comprehensive income (loss) before tax	3,849	(1,298)	8,614	2,333
Income tax (benefit) expense	(438)	282	(19)	105
Other comprehensive income (loss), net of tax	4,287	(1,580)	8,633	2,228
Total comprehensive income (loss)	$ 6,809	$ (1,435)	$ 9,108	$ 1,127