Selected Segment Data (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Net sales:	$ 507.4	$ 462.1	$ 1,605.5	$ 1,237.3
Operating profit (loss):	47.6	42.9	224.7	57.1
Other operating credits and charges, net	16.1	(1.2)	9.1	(1.2)
(Gain) loss on sale or impairment of long-lived assets	(0.3)	(4.3)	0.4	(4.5)
Gain on acquisition	0	0	35.9	0
Early debt extinguishment	(0.8)	0	(0.8)	(52.2)
General corporate and other expenses, net	(22.1)	(18.1)	(65.9)	(56.3)
Foreign currency gains (losses)	1.0	0.4	(3.3)	(2.3)
Investment income	1.7	4.1	8.3	11.7
Interest expense, net of capitalized interest	(7.6)	(10.7)	(28.0)	(36.4)
Income (loss) from continuing operations before taxes	41.9	38.7	248.1	(24.7)
Provision (benefit) for income taxes	4.4	7.7	51.6	(5.6)
Income (loss) from continuing operations	37.5	31.0	196.5	(19.1)
OSB [Member]
Segment Reporting Information [Line Items]
Net sales:	245.4	226.6	838.3	571.0
Operating profit (loss):	30.2	49.3	223.7	66.0
Siding [Member]
Segment Reporting Information [Line Items]
Net sales:	149.0	134.1	435.5	384.2
Operating profit (loss):	22.5	20.3	70.3	56.4
Engineered Wood Products [Member]
Segment Reporting Information [Line Items]
Net sales:	71.8	61.5	196.1	161.8
Operating profit (loss):	(2.0)	(3.0)	(10.6)	(9.3)
South America [Member]
Segment Reporting Information [Line Items]
Net sales:	41.5	42.0	130.9	127.1
Operating profit (loss):	5.3	4.5	17.8	11.2
Other [Member]
Segment Reporting Information [Line Items]
Net sales:	3.9	3.4	10.3	10.1
Operating profit (loss):	(2.1)	(2.6)	(6.1)	(7.8)
Intersegment elimination [Member]
Segment Reporting Information [Line Items]
Net sales:	(4.2)	(5.5)	(5.6)	(16.9)
Unconsolidated Affiliates [Member]
Segment Reporting Information [Line Items]
Other Operating Credits and Charges Associated with Unconsolidated Affiliates	$ 0	$ 0	$ (2.7)	$ 0