Other Operating Credits and Charges, Net severance (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended						3 Months Ended		12 Months Ended
	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Severance [Member]	Dec. 31, 2011 Severance [Member]	Dec. 31, 2010 Severance [Member]	Mar. 31, 2012 OSB Mills Construction Related Legal Reserves [Member]	Sep. 30, 2011 OSB Mills Construction Related Legal Reserves [Member]	Dec. 31, 2011 OSB Mills Construction Related Legal Reserves [Member]
Restructuring Cost and Reserve [Line Items]
Reserves For Timber Obligations		$ 1.5	$ 0.8	$ 1.5	$ 0
Accrual for Environmental Loss Contingencies, Provision for New Losses		0.9	0	(0.9)	0
Severance Costs			0.5	1.1	0				0.3	(0.4)	(1.1)
Restructuring Reserve [Roll Forward]
Beginning Balance						1.5	0.6	2.1
Charged to expense, continuing operations						1.0	1.9	0.5
Payments						(1.8)	(1.0)	(2.0)
Ending Balance						0.7	1.5	0.6
Reductions, net of additions, to product related contingency reserves	$ (10.7)		$ (5.0)	$ (11.5)	$ (2.5)