Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Current period cash flow hedging activity, tax benefit	$ (73)	$ (357)	$ (838)
Reclassification of hedging activities into earnings, tax benefit	(419)	(191)	(489)
Current period pension and postretirement plan adjustment, tax benefit	(1,098)	(1,222)	(3,292)
Reclassification of pension and post retirement adjustments into earnings, tax benefit	$ (408)	$ (420)	$ (313)