Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Change in Accumulated Other Comprehensive Loss [Roll Forward]
Ending balance	$ (141,040)	$ (128,372)
Total Accumulated Comprehensive Loss
Change in Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(128,372)	(110,946)
Change	(14,533)	(16,994)
Tax effect	1,865	(432)
Ending balance	(141,040)	(128,372)
Foreign Currency Translation
Change in Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(4,005)	(2,661)
Change	2,364	(1,344)
Tax effect	0	0
Ending balance	(1,641)	(4,005)
Derivative Instruments
Change in Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(2,370)	(1,121)
Change	3,268	(624)
Tax effect	(409)	(625)
Ending balance	489	(2,370)
Pension and Other Postretirement Benefits
Change in Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(121,997)	(107,164)
Change	(20,165)	(15,026)
Tax effect	2,274	193
Ending balance	$ (139,888)	$ (121,997)