Environmental Matters (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 DisposalSite	Dec. 31, 2011	Dec. 31, 2010
Environmental Matters (Textual) [Abstract]
Number of disposal sites	19
Environmental expenses	$ 7,000,000	$ 7,000,000	$ 7,000,000
Environmental liabilities	12,616,000	13,539,000
Capital expenditures related to environmental programs	$ 2,000,000	$ 3,000,000	$ 2,000,000