Selected Segment Data (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Segment Reporting Information [Line Items]
Net sales:	$ 467.8	$ 350.6	$ 1,257.1	$ 1,044.7
Operating profit (loss):	43.5	(72.7)	60.4	(114.5)
Other operating credits and charges, net	(1.2)	9.8	(1.2)	11.2
Loss on sale or impairment of long-lived assets	(4.3)	(65.0)	(4.5)	(73.0)
General corporate and other expenses, net	(18.1)	(15.2)	(56.3)	(49.6)
Foreign currency gains (losses)	0.4	(4.0)	(2.3)	(1.6)
Early debt extinguishment	0	0	(52.2)	0
Investment income	4.1	16.7	11.7	24.2
Interest expense, net of capitalized interest	(10.7)	(14.2)	(36.4)	(42.6)
Income (loss) from continuing operations before taxes	39.3	(80.2)	(21.4)	(151.2)
Provision (benefit) for income taxes	7.9	(20.9)	(4.4)	(36.1)
Income (loss) from continuing operations	31.4	(59.3)	(17.0)	(115.1)
OSB [Member]
Segment Reporting Information [Line Items]
Net sales:	226.6	138.8	571.0	411.4
Operating profit (loss):	49.3	(16.0)	66.0	(48.0)
Siding [Member]
Segment Reporting Information [Line Items]
Net sales:	134.1	112.0	384.2	336.6
Operating profit (loss):	20.3	11.8	56.4	35.9
Engineered Wood Products [Member]
Segment Reporting Information [Line Items]
Net sales:	61.5	54.9	161.8	156.9
Operating profit (loss):	(3.0)	(3.2)	(9.3)	(11.9)
South America [Member]
Segment Reporting Information [Line Items]
Net sales:	42.0	36.3	127.1	111.1
Operating profit (loss):	4.5	2.3	11.2	10.1
Other [Member]
Segment Reporting Information [Line Items]
Net sales:	9.1	9.5	29.9	30.4
Operating profit (loss):	(2.0)	(3.2)	(4.5)	(5.9)
Intersegment elimination [Member]
Segment Reporting Information [Line Items]
Net sales:	$ (5.5)	$ (0.9)	$ (16.9)	$ (1.7)