Revenue Disaggregation of revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,828.0	$ 2,733.9	$ 2,233.4
SmartSide Strand siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	746.3	662.4	567.6
SmartSide Fiber siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	106.4	111.3	108.1
CanExel siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	37.3	49.4	43.2
OSB - commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	795.2	841.8	661.1
OSB - value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	722.5	669.6	515.1
LVL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	140.9	144.3	122.1
LSL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	59.2	46.7	37.8
I Joist [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	122.1	116.8	99.4
Plywood [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	28.7	25.1	15.8
Other products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	69.4	66.5	63.2
Siding
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	942.3	884.0	752.3
Siding | SmartSide Strand siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	724.8	646.3	549.5
Siding | SmartSide Fiber siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	106.4	111.3	108.1
Siding | CanExel siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	37.3	49.4	43.2
Siding | OSB - commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	39.4	66.9	40.8
Siding | OSB - value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	22.5	0.0	1.8
Siding | LVL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Siding | LSL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Siding | I Joist [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Siding | Plywood [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Siding | Other products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	11.9	10.1	8.9
OSB
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,305.2	1,302.5	1,027.7
OSB | SmartSide Strand siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
OSB | SmartSide Fiber siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
OSB | CanExel siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
OSB | OSB - commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	746.0	765.5	626.0
OSB | OSB - value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	550.9	524.7	390.3
OSB | LVL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
OSB | LSL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
OSB | I Joist [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
OSB | Plywood [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
OSB | Other products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8.3	12.3	11.4
Engineered Wood Products
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	390.9	365.9	296.9
Engineered Wood Products | SmartSide Strand siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Engineered Wood Products | SmartSide Fiber siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Engineered Wood Products | CanExel siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Engineered Wood Products | OSB - commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	9.9	9.4	0.1
Engineered Wood Products | OSB - value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	13.9	13.2	10.7
Engineered Wood Products | LVL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	140.9	144.3	122.1
Engineered Wood Products | LSL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	59.2	46.8	37.8
Engineered Wood Products | I Joist [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	122.1	116.9	99.4
Engineered Wood Products | Plywood [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	28.7	25.1	15.8
Engineered Wood Products | Other products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	16.2	10.2	11.0
South America
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	160.8	155.3	136.9
South America | SmartSide Strand siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	21.5	19.7	19.6
South America | SmartSide Fiber siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
South America | CanExel siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
South America | OSB - commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	131.7	0.0
South America | OSB - value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	135.2	131.7	112.3
South America | LVL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
South America | LSL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
South America | I Joist [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
South America | Plywood [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
South America | Other products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4.1	3.9	5.0
Other
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	28.9	30.0	26.9
Other | SmartSide Strand siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Other | SmartSide Fiber siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Other | CanExel siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Other | OSB - commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Other | OSB - value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Other | LVL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Other | LSL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Other | I Joist [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Other | Plywood [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Other | Other products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	28.9	30.0	26.9
Intersegment sales
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(0.1)	(3.8)	(7.3)
Intersegment sales | SmartSide Strand siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	(3.6)	(1.5)
Intersegment sales | SmartSide Fiber siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Intersegment sales | CanExel siding [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Intersegment sales | OSB - commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(0.1)	0.0	(5.8)
Intersegment sales | OSB - value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Intersegment sales | LVL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Intersegment sales | LSL [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	(0.1)	0.0
Intersegment sales | I Joist [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	(0.1)	0.0
Intersegment sales | Plywood [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Intersegment sales | Other products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Commodity [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	823.9	866.9	676.9
Commodity [Member] | Siding
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	39.4	66.9	40.8
Commodity [Member] | OSB
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	746.0	765.5	626.0
Commodity [Member] | Engineered Wood Products
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	38.6	34.5	15.9
Commodity [Member] | South America
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Commodity [Member] | Other
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Commodity [Member] | Intersegment sales
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(0.1)	0.0	(5.8)
Value-add [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,934.7	1,800.5	1,493.3
Value-add [Member] | Siding
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	891.0	807.0	702.6
Value-add [Member] | OSB
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	550.9	524.7	390.3
Value-add [Member] | Engineered Wood Products
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	336.1	321.2	270.0
Value-add [Member] | South America
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	156.7	151.4	131.9
Value-add [Member] | Other
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	0.0	0.0
Value-add [Member] | Intersegment sales
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0.0	(3.8)	(1.5)
Other products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	69.4	66.5	63.2
Other products [Member] | Siding
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	11.9	10.1	8.9
Other products [Member] | OSB
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8.3	12.3	11.4
Other products [Member] | Engineered Wood Products
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	16.2	10.2	11.0
Other products [Member] | South America
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4.1	3.9	5.0
Other products [Member] | Other
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	28.9	30.0	26.9
Other products [Member] | Intersegment sales
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0.0	$ 0.0	$ 0.0