Liabilities for Dispositions and Discontinued Operations Site Liabilities Rollforward (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	$ 81,695	$ 90,824	$ 93,160	$ 98,591
Expenditures	(9,926)	(9,209)	(8,632)
Increase (Reduction) to Liabilities	797	6,873	3,201
Augusta, Georgia [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	12,100	13,900	14,900
Expenditures	(800)	(1,100)
Increase (Reduction) to Liabilities	(1,000)	100
Spartanburg, South Carolina [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	14,000	14,700	14,300
Expenditures	(900)	(1,000)
Increase (Reduction) to Liabilities	200	1,400
East Point, Georgia [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	10,900	11,000	12,300
Expenditures	(1,000)	(1,300)
Increase (Reduction) to Liabilities	900	0
Baldwin, Florida [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	9,100	9,700	10,000
Expenditures	(900)	(800)
Increase (Reduction) to Liabilities	300	500
Other SWP sites [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	20,900	26,300	31,800
Expenditures	(3,600)	(2,200)
Increase (Reduction) to Liabilities	(1,800)	(3,300)
Total SWP sites [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	67,000	75,600	83,300
Expenditures	(7,200)	(6,400)
Increase (Reduction) to Liabilities	(1,400)	(1,300)
Port Angeles, Washington [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	9,500	9,300	4,400
Expenditures	(1,700)	(2,200)
Increase (Reduction) to Liabilities	1,900	7,100
All other sites [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Liability	5,200	5,900	5,500
Expenditures	(1,000)	(600)
Increase (Reduction) to Liabilities	$ 300	$ 1,000