Consolidated statements of comprehensive income (loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,513	$ (7,246)	$ 5,433	$ (9,434)
Other comprehensive income (loss), net of tax:
Foreign currency translation (net of tax effect of $0, $0, $0 and $0, respectively)	(2,047)	1,154	(1,842)	1,511
Retirement related benefit plans (net of tax effect of $(17), $0, $(7) and $0, respectively)	118	(33)	106	(44)
Total other comprehensive income (loss)	(1,929)	1,121	(1,736)	1,467
Comprehensive income (loss)	$ (416)	$ (6,125)	$ 3,697	$ (7,967)