Commitments and Contingencies - Narrative (Details) $ in Millions, $ in Millions		1 Months Ended
	Apr. 19, 2021 CAD ($)	May 31, 2020 CAD ($)	Sep. 25, 2021 USD ($) sawmill	Aug. 28, 2021 USD ($)	Dec. 31, 2017
Guarantor Obligations [Line Items]
Number of lumbar mills | sawmill			6
Anti-dumping duty				160.00%	600.00%
Countervailing duty				740.00%	1400.00%
Rights to duty refunds				$ 112
Duties receivable			$ 20
IESO Investigation of the Kapuskasing Facility
Guarantor Obligations [Line Items]
Penalty		$ 25.0
Penalty due immediately		3.0
Penalty due over time		$ 12.0
Penalty payment period (years)		10 years
Penalty deferred		$ 10.0
Settlement	$ 12.0
Settlement payment period (years)	5 years
Settlement due immediately	$ 4.5
Settlement due over time	7.5
Settlement suspended	$ 10.4
LignoTech Florida
Guarantor Obligations [Line Items]
Ownership percentage			45.00%
Borregaard ASA | LignoTech Florida
Guarantor Obligations [Line Items]
Ownership percentage			55.00%
Financial Standby Letter of Credit
Guarantor Obligations [Line Items]
Letters of credit			$ 40
Surety Bond
Guarantor Obligations [Line Items]
Guarantees			86
Contract Guarantee
Guarantor Obligations [Line Items]
Guarantees			$ 32