Commitments And Contingencies (Other Contingencies) (Details) (USD $)			3 Months Ended						12 Months Ended				12 Months Ended
	Dec. 31, 2012	Mar. 31, 2007	Dec. 31, 2011 Environmental Claims For A Site In Goodyear Arizona [Member]	Dec. 31, 2008 Environmental Claims For A Site In Goodyear Arizona [Member]	Dec. 31, 2012 Environmental Claims For A Site In Goodyear Arizona [Member]	Dec. 31, 2007 Environmental Claims For A Site In Goodyear Arizona [Member]	Jul. 31, 2006 Environmental Claims For A Site In Goodyear Arizona [Member]	Dec. 31, 2012 Environmental Claims For Crab Orchard National Wildlife Refuge Superfund Site [Member] acre	Dec. 31, 2011 Environmental Claims For Site In Roseland New Jersey [Member] Homeowner	Dec. 31, 2011 Environmental Claims For Site In Roseland New Jersey [Member] Home	Apr. 15, 2011 Environmental Claims For Site In Roseland New Jersey [Member] Home	Jan. 08, 2010 Merrimac Securities Class Action Lawsuit [Member]	Dec. 31, 2012 Negligence Lawsuit Rising From Fire Damage [Member] Lawsuit	Jan. 11, 2013 Subsequent Event [Member]
Loss Contingencies [Line Items]
Estimated liability				$ 65,200,000	$ 49,800,000	$ 41,500,000
Additional charge			30,300,000	24,300,000
Accrued environmental loss contingencies, current portion of total gross estimated liability					16,000,000
Other receivables					10,900,000
Stock price per share												$ 16.00
Settlement fund														2,000,000
Contribution by Company to settlement fund														150,000
Estimate of lost profits													260,000,000
Approximate size of referenced site, acres								55,000
Number of separate lawsuits consolidated into one lawsuit													5
Approximate number of homes tested for contaminants									40	40
Number of homes where contaminants were found									3	3
Number of tenants who filed a separate lawsuit											1
Number of members in the purported class									141	141
Loss contingency reimbursement rate							21.00%
Residual value guarantee liability	5,200,000	14,100,000
Property, Plant, and Equipment, Fair Value Disclosure		$ 22,100,000