Selected Segment Data (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net sales	$ 2,828.0	$ 2,733.9	$ 2,233.4
Income from operations	526.1	532.8	210.2
Other operating credits and charges, net	2.2	(4.9)	(17.4)
(Gain) loss on sale or impairment of long-lived assets	(10.8)	(6.8)	8.4
Other General Expense	(111.7)	(108.1)	(102.3)
Other Nonoperating Income (Expense)	(3.9)	(13.8)	(21.4)
Foreign currency gains (losses)	0.4	(4.4)	2.1
Investment income	17.6	10.5	8.2
Interest expense, net of capitalized interest	(15.8)	(19.3)	(32.1)
Loss from continuing operations before taxes	521.1	510.2	170.1
Provision (benefit) for income taxes	(122.3)	(119.1)	(19.8)
Income from continuing operations	398.8	391.1	150.3
Depreciation and amortization	120.0	123.3	112.8
Capital Expenditures	214.2	148.6	124.8
Siding
Segment Reporting Information [Line Items]
Net sales	942.3	884.0	752.3
Income from operations	201.6	188.7	128.0
Depreciation and amortization	32.3	30.9	27.4
Capital Expenditures	117.1	63.0	49.9
OSB
Segment Reporting Information [Line Items]
Net sales	1,305.2	1,302.5	1,027.7
Income from operations	395.7	427.3	187.8
Depreciation and amortization	58.3	61.6	58.6
Capital Expenditures	54.9	58.4	49.3
Engineered Wood Products
Segment Reporting Information [Line Items]
Net sales	390.9	365.9	296.9
Income from operations	19.5	15.7	(4.6)
Depreciation and amortization	15.1	15.8	12.7
Capital Expenditures	9.9	6.0	5.3
South America
Segment Reporting Information [Line Items]
Net sales	160.8	155.3	136.9
Income from operations	31.0	24.3	17.0
Depreciation and amortization	9.1	9.1	8.6
Capital Expenditures	28.3	17.5	8.7
Other
Segment Reporting Information [Line Items]
Net sales	28.9	30.0	26.9
Income from operations	(4.3)	(3.4)	(1.5)
Depreciation and amortization	2.0	2.8	2.3
Capital Expenditures	1.2	1.0	8.1
Intersegment sales
Segment Reporting Information [Line Items]
Net sales	(0.1)	(3.8)	(7.3)
Unallocated Amount to Segment
Segment Reporting Information [Line Items]
Depreciation and amortization	3.2	3.1	3.2
Capital Expenditures	$ 2.8	$ 2.7	$ 3.5