Liabilities for Dispositions and Discontinued Operations Analysis of Activity (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance, January 1	$ 90,824	$ 93,160	$ 98,591
Expenditures charged to liabilities	(9,926)	(9,209)	(8,632)
Increase to liabilities	797	6,873	3,201
Balance, December 31	81,695	90,824	93,160
Less: Current Portion	(8,105)	(9,931)	(11,500)
Non-Current Portion	$ 73,590	$ 80,893	$ 81,660