Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net income (loss)	$ (78,815)	$ 2,909	$ (86,217)	$ 12,322
Other comprehensive income (loss):
Pension and other post-retirement benefit adjustments, net of tax	1,422	1,063	4,872	5,090
Change in fair value of derivative instruments, net of tax	597	501	199	(1,200)
Foreign currency translation adjustments, net of tax	2,650	485	9,647	811
Other comprehensive income, net of tax	4,669	2,049	14,718	4,701
Comprehensive income (loss)	$ (74,146)	$ 4,958	$ (71,499)	$ 17,023