Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Rebates accrued	$ 18.7		$ 24.2
Consignment inventory	19.0		$ 18.3
Revenue by product line and product type	691.3	$ 610.9
Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	227.0	214.0
OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	313.3	268.4
EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	100.7	82.1
South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	42.4	37.8
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	7.9	8.7
Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	(0.1)
SmartSide Strand siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	171.9	162.3
SmartSide Strand siding [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	165.1	156.1
SmartSide Strand siding [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
SmartSide Strand siding [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
SmartSide Strand siding [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	6.8	6.2
SmartSide Strand siding [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
SmartSide Strand siding [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
SmartSide Fiber siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	25.9	28.7
SmartSide Fiber siding [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	25.9	28.7
SmartSide Fiber siding [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
SmartSide Fiber siding [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
SmartSide Fiber siding [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
SmartSide Fiber siding [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
SmartSide Fiber siding [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
CanExel siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	13.9	14.3
CanExel siding [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	13.9	14.3
CanExel siding [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
CanExel siding [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
CanExel siding [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
CanExel siding [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
CanExel siding [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
OSB - commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	192.6	164.8
OSB - commodity [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	8.7	12.4
OSB - commodity [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	181.1	151.3
OSB - commodity [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	2.8	1.1
OSB - commodity [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
OSB - commodity [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
OSB - commodity [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
OSB - value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	177.3	146.6
OSB - value-add [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	9.2	0.0
OSB - value-add [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	129.1	113.1
OSB - value-add [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	4.1	2.9
OSB - value-add [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	34.9	30.6
OSB - value-add [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
OSB - value-add [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LVL [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	36.6	33.0
LVL [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LVL [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LVL [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	36.6	33.0
LVL [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LVL [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LVL [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LSL [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	13.3	10.6
LSL [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LSL [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LSL [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	13.3	10.6
LSL [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LSL [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
LSL [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
I Joist [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	32.1	25.7
I Joist [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
I Joist [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
I Joist [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	32.1	25.7
I Joist [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
I Joist [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
I Joist [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Plywood [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	7.6	4.8
Plywood [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Plywood [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Plywood [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	7.6	4.8
Plywood [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Plywood [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Plywood [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	20.1	20.1
Other [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	4.2	2.5
Other [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	3.1	4.0
Other [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	4.2	4.0
Other [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.7	1.0
Other [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	7.9	8.7
Other [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	(0.1)
Commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	200.2	169.6
Commodity [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	8.7	12.4
Commodity [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	181.1	151.3
Commodity [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	10.4	5.9
Commodity [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Commodity [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Commodity [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	471.0	421.2
Value-add [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	214.1	199.1
Value-add [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	129.1	113.1
Value-add [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	86.1	72.2
Value-add [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	41.7	36.8
Value-add [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Value-add [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.0	0.0
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	20.1	20.1
Other [Member] | Siding [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	4.2	2.5
Other [Member] | OSB [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	3.1	4.0
Other [Member] | EWP [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	4.2	4.0
Other [Member] | South America [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	0.7	1.0
Other [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	7.9	8.7
Other [Member] | Intersegment [Member]
Disaggregation of Revenue [Line Items]
Revenue by product line and product type	$ 0.0	$ (0.1)