Other Operating Credits and Charges, Net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Gain Contingencies [Line Items]
Adjustments related to prior year inventory									$ (1.5)	$ 0	$ 0
Reversal of severance									(0.5)	(1.1)	0
Other Postretirement Benefit Expense									1.6
Adjustments to retirement accounts									3.8	0	0
Additions to litigation reserves									0	0	(2.2)
Addition to environmental related contingency reserves							(0.9)		0	0.9	0
Reductions, net of additions, to product related contingency reserves						10.7			5.0	11.5	2.5
Other Expenses											0.5
Product Warranty Accrual, Period Increase (Decrease)									1.8	0.4	0
Timber related reserves							1.5		0.8	1.5	0
Other Cost and Expense, Operating									1.1	(0.2)	(0.4)
Other operating income (expense), net	4.1	(1.2)	(0.2)	0.2	0	9.8	0.6	0.8	2.9	11.2	(0.1)
Assessment											1.0
OSB Mills Construction Related Legal Reserves [Member]
Gain Contingencies [Line Items]
Reversal of severance				(0.3)		0.4				1.1
Siding [Member]
Gain Contingencies [Line Items]
Product Warranty Accrual, Period Increase (Decrease)									(1.0)
OSB Siding [Member]
Gain Contingencies [Line Items]
Product Warranty Accrual, Period Increase (Decrease)									(0.8)
Hardboard Siding Reserves [Member]
Gain Contingencies [Line Items]
Product Warranty Accrual, Period Increase (Decrease)									$ 3.6