Selected Segment Data (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
Segment Reporting Information [Line Items]
Net sales	$ 458.7	$ 467.8	$ 427.8	$ 361.5	$ 312.2	$ 350.6	$ 362.4	$ 331.7	$ 1,715.8	$ 1,356.9	$ 1,383.6
Operating income (loss)									107.4	(140.1)	(7.6)
Other operating credits and charges, net	4.1	(1.2)	(0.2)	0.2	0	9.8	0.6	0.8	2.9	11.2	(0.1)
(Gain) loss on sale or impairment of long-lived assets	(0.4)	(4.3)	(0.1)	(0.1)	(0.9)	(65.0)	(2.5)	(5.5)	(4.9)	(73.9)	(2.4)
General corporate and other expenses, net	(22.4)	(18.1)	(18.2)	(20.1)	(16.9)	(15.2)	(16.5)	(17.8)	(78.7)	(66.4)	(73.4)
Foreign currency gains (losses)									(2.7)	(1.0)	2.2
Other-than-temporary impairment of investments									0	14.8	17.0
Other-than-temporary investment impairment	0	0	0	0	(14.8)	0	0	0	0	(14.8)	(17.0)
Other non-operating Expense									34.9	1.0	(2.2)
Investment income	3.1	4.1	3.4	4.2	4.5	16.7	3.5	4.0	14.8	28.7	38.4
Interest expense, net of capitalized interest	(12.9)	(10.7)	(13.1)	(12.6)	(14.3)	(14.2)	(14.4)	(14.0)	(49.3)	(56.9)	(63.9)
Loss from continuing operations before taxes	61.1	39.3	(48.3)	(12.4)	(59.8)	(80.2)	(41.3)	(29.7)	39.7	(211.0)	(54.3)
Provision (benefit) for income taxes	(12.0)	(7.9)	11.1	1.2	3.0	20.9	8.4	6.8	(7.6)	39.1	22.1
Income (loss) from continuing operations	49.1	31.4	(37.2)	(11.2)	(56.8)	(59.3)	(32.9)	(22.9)	32.1	(171.9)	(32.2)
Other Depreciation and Amortization									73.9	78.9	82.0
Payments to Acquire Property, Plant, and Equipment									31.2	21.4	14.5
OSB [Member]
Segment Reporting Information [Line Items]
Net sales	243.1	226.6	194.9	149.0	130.6	138.8	140.6	132.1	814.1	542.0	602.7
Operating income (loss)	58.0	49.3	17.0	(0.3)	(15.5)	(16.0)	(22.9)	(9.1)	124.0	(63.5)	25.8
Other Depreciation and Amortization									33.1	36.3	37.4
Payments to Acquire Property, Plant, and Equipment									10.1	8.9	7.1
Siding [Member]
Segment Reporting Information [Line Items]
Net sales	116.7	134.1	137.0	113.1	93.0	112.0	118.6	106.2	500.9	429.8	427.8
Operating income (loss)	11.0	20.3	19.4	16.8	6.2	11.8	11.3	12.7	67.4	42.0	51.3
Other Depreciation and Amortization									15.5	15.5	18.1
Payments to Acquire Property, Plant, and Equipment									8.7	5.9	5.6
Engineered Wood Products [Member]
Segment Reporting Information [Line Items]
Net sales	51.6	61.5	51.7	48.6	46.4	54.9	53.6	48.3	213.4	203.3	192.0
Operating income (loss)	(4.6)	(3.0)	(3.4)	(2.8)	(3.6)	(3.2)	(3.2)	(5.5)	(13.9)	(15.5)	(21.3)
Other Depreciation and Amortization									11.0	12.6	13.1
Payments to Acquire Property, Plant, and Equipment									2.5	2.0	0.4
South America [Member]
Segment Reporting Information [Line Items]
Net sales	41.7	42.0	42.7	42.4	33.8	36.3	39.5	35.3	168.8	144.9	124.7
Operating income (loss)	6.8	4.5	3.6	3.1	1.5	2.3	4.2	3.6	18.0	11.6	7.2
Other Depreciation and Amortization									12.0	11.6	10.0
Payments to Acquire Property, Plant, and Equipment									4.6	2.7	1.1
Other
Segment Reporting Information [Line Items]
Net sales	7.5	9.1	10.7	10.0	9.1	9.5	10.4	10.5	37.4	39.4	42.9
Operating income (loss)	(1.2)	(2.0)	(1.9)	(0.7)	(6.6)	(3.2)	(2.0)	(0.7)	(5.7)	(12.5)	(1.1)
Other Depreciation and Amortization									0.6	0.8	1.1
Payments to Acquire Property, Plant, and Equipment									0.9	0.2	0
Intersegment sales
Segment Reporting Information [Line Items]
Net sales	(1.9)	(5.5)	(9.2)	(1.6)	(0.7)	(0.9)	(0.3)	(0.7)	(18.8)	(2.5)	(6.5)
Unallocated Amount to Segment [Member]
Segment Reporting Information [Line Items]
Other Depreciation and Amortization									1.7	2.1	2.3
Payments to Acquire Property, Plant, and Equipment									$ 4.4	$ 1.7	$ 0.3