Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Derivatives qualifying as hedges tax expense (benefit)	$ (357)	$ (838)	$ 477
Reclassification adjustment from AOCI on derivatives tax expense (benefit)	(191)	(489)	(95)
Pension and other postretirement benefit plans tax expense (benefit)	(1,222)	(3,292)	5,531
Finalization of pension and non pension postretirement plan valuation tax expense	0	0	718
Amortization adjustment from AOCI pension and other post retirement plans, tax expense (benefit)	$ (420)	$ (313)	$ (740)