Liabilities for Dispositions and Discontinued Operations Site Liabilities Rollforward (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	$ 90,824	$ 93,160	$ 98,591	$ 104,575
Expenditures	(9,209)	(8,632)	(8,095)
Increase (Reduction) to Liabilities	6,873	3,201	2,111
Augusta, Georgia [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	13,900	14,900	15,100
Expenditures	(1,100)	(1,300)
Increase (Reduction) to Liabilities	100	1,100
Spartanburg, South Carolina [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	14,700	14,300	14,900
Expenditures	(1,000)	(800)
Increase (Reduction) to Liabilities	1,400	200
East Point, Georgia [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	11,000	12,300	14,700
Expenditures	(1,300)	(1,100)
Increase (Reduction) to Liabilities	0	(1,300)
Baldwin, Florida [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	9,700	10,000	8,400
Expenditures	(800)	(800)
Increase (Reduction) to Liabilities	500	2,400
Other SWP sites [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	26,300	31,800	35,400
Expenditures	(2,200)	(2,000)
Increase (Reduction) to Liabilities	(3,300)	(1,600)
Total SWP sites [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	75,600	83,300	88,500
Expenditures	(6,400)	(6,000)
Increase (Reduction) to Liabilities	(1,300)	800
Port Angeles, Washington [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	9,300	4,400	4,400
Expenditures	(2,200)	(2,000)
Increase (Reduction) to Liabilities	7,100	2,000
All other sites [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	5,900	5,500	5,700
Expenditures	(600)	(600)
Increase (Reduction) to Liabilities	$ 1,000	$ 400