Commitments and Contingencies (Details 2) (USD $)		3 Months Ended		12 Months Ended			1 Months Ended	3 Months Ended				12 Months Ended	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Legal Matters	Dec. 31, 2011 Legal Matters	Sep. 30, 2010 Boynton item	Sep. 30, 2009 Boynton item	Apr. 30, 2011 Boynton	Feb. 29, 2012 Fentress Families Trust item	Dec. 31, 2012 Fentress Families Trust item	Dec. 31, 2012 Neil Wallace	Dec. 31, 2011 Oxford Mining Company	Dec. 31, 2012 Reechcraft	Sep. 30, 2008 Archstone item	Dec. 31, 2012 CPM	Dec. 31, 2012 Repair cost Archstone	Dec. 31, 2012 Lost lease payments Archstone	Dec. 31, 2012 Class action defense fees Archstone	Dec. 31, 2012 Tenant lawsuit against Archstone Archstone
Commitments and Contingencies
Long term capital commitments on property, plant and equipment	$ 2,000,000
Legal fees		600,000	300,000
Potential loss for unresolved matters		18,000,000			43,000,000
Total liability accrued		18,000,000
Verdict for damages				7,300,000	8,700,000
Number of plaintiffs				46	8		383
Constructive trust amount ordered by trial court						16,000,000
Court ordered judgment						16,000,000
Number of defendants							15
Damages for removal and remediation of fly ash and water supply							850,000,000
Damages for vexation							1,900,000,000
Damages for others							8,000,000
Damages for properties plus prejudgment interest, attorney fees and costs							55,000,000
Additional damages sought by other plaintiffs							307,200,000
Number of insurers who have denied coverage								1
Loss contingency damages sought value									$ 10,000,000	$ 5,000,000	$ 3,100,000		$ 500,000	$ 36,000,000	$ 19,000,000	$ 7,000,000	$ 7,000,000
Number of buildings												21