Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (32,417)	$ (63,146)	[1]	$ (84,455)
Other comprehensive income (loss) before tax:
Foreign currency translation adjustment	3,865	(9,241)		10,607
Foreign currency hedge	282	658		(1,802)
Defined benefit pension plans
Net actuarial gain (loss) arising during period	(421)	109		3,226
Settlement cost during period	226	0		0
Prior service cost arising during period	0	(669)		0
Amortization of prior service cost	33	0		0
Amortization of net actuarial (gain) loss	0	(78)		71
Other comprehensive income (loss), before tax	3,985	(9,221)		12,102
Tax (provision) benefit attributable to other comprehensive income (loss)	217	(3,045)		(2,898)
Other comprehensive income (loss), net of tax	4,202	(12,266)		9,204
Total comprehensive loss	$ (28,215)	$ (75,412)		$ (75,251)

[1] Income (loss) from continuing operations, net income (loss) and the related earnings (loss) per share amounts for each of the quarters in 2018 are revised from those originally reported to correct errors in income tax expense (benefit) associated with the measurement of valuation allowances on deferred tax assets. Based on an analysis of quantitative and qualitative factors, the Company determined the related impacts were not material to its previously filed interim consolidated financial statements, and therefore, amendments of previously filed reports are not required.