Selected Segment Data (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Net sales:	$ 537.5	$ 361.5
Operating profit (loss):	89.2	(2.1)
Other operating credits and charges, net	(1.6)	0.2
Loss on sale or impairment of long-lived assets	0	(0.1)
General corporate and other expenses, net	(22.6)	(20.1)
Foreign currency gains (losses)	(0.7)	(0.1)
Investment income	3.5	4.2
Interest expense, net of capitalized interest	(10.6)	(12.6)
Income (loss) from continuing operations before taxes	88.6	(12.4)
Provision (benefit) for income taxes	23.2	(1.2)
Income (loss) from continuing operations	65.4	(11.2)
OSB [Member]
Segment Reporting Information [Line Items]
Net sales:	286.7	149.0
Operating profit (loss):	98.1	(0.3)
Siding [Member]
Segment Reporting Information [Line Items]
Net sales:	133.8	113.1
Operating profit (loss):	20.7	16.8
Engineered Wood Products [Member]
Segment Reporting Information [Line Items]
Net sales:	63.4	48.6
Operating profit (loss):	(3.5)	(2.8)
South America [Member]
Segment Reporting Information [Line Items]
Net sales:	45.1	42.4
Operating profit (loss):	6.2	3.1
Other [Member]
Segment Reporting Information [Line Items]
Net sales:	9.1	10.0
Operating profit (loss):	(0.9)	(0.7)
Intersegment elimination [Member]
Segment Reporting Information [Line Items]
Net sales:	$ (0.6)	$ (1.6)