Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other Comprehensive Income [Abstract]
Pension and post-retirement benefits, Gross Amount	$ (16,652)	$ (44,377)	$ (2,682)
Foreign currency translation adjustments, Gross Amount	102	(350)	0
Change in fair value of derivative, Gross Amount	8,062	8,114	(2,506)
Total Other Comprehensive Income (Loss), Other Comprehensive Income (Loss), Gross Amount	(8,488)	(36,613)	(5,188)
Pension and post-retirement benefits, Income Tax (Provision) Benefit	6,382	16,994	1,028
Foreign currency translation adjustments, Income Tax (Provision) Benefit	0	0	0
Change in fair value of derivative, Income Tax (Provision) Benefit	(2,845)	(2,915)	986
Total other comprehensive income (loss), Income Tax (Provision) Benefit	3,537	14,079	2,014
Pension and post-retirement benefits	(10,270)	(27,383)	(1,654)
Foreign currency translation adjustments, Net Amount	102	(350)	0
Change in fair value of derivative, Net Amount	5,217	5,199	(1,520)
Total comprehensive loss, net of taxes	$ (4,951)	$ (22,534)	$ (3,174)