Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Tax expense (benefit) on unrealized gain (loss) on derivatives	$ (456)	$ (470)	$ (27)
Tax expense (benefit) on foreign currency translation adjustment	(60)	(196)	2
Tax (expense) benefit on pension and other post-retirement benefits liability adjustment	$ (1,024)	$ 339	$ 1,205