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Approximate total response costs identified in the notice of liability.

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Commitments and contingencies.

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Countervailing duty and anti dumping duty cash deposits on softwood lumber paid.

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Estimated amount of contributions if annuities are purchased.

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Loss contingency direct cost recognized.

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Loss contingency minimum amount of alleged warehouse damage.

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Maximum deficit from partial wind up of pension plans to be funded.

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Percentage of operating limit on retirement year.

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Preliminary determination anti dumping rate on certain canadian softwood lumber imported to the us market.

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Preliminary determination countervailing duty rate on certain canadian softwood lumber imported to the us market.

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Purchase of annuities to reconcile the pension deficits period.

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Total costs accrued as of the balance sheet date for environmental loss contingencies.

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The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.

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Amount of cash inflow from the collection of receivables related to a loss contingency.

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Amount of letters of credit and other surety bonds that are available for the future payment of malpractice claims.

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Commitments and Contingencies - Additional Information (Detail) $ in Millions		3 Months Ended			4 Months Ended	6 Months Ended	9 Months Ended
	May 23, 2023	Sep. 30, 2026 USD ($)	Jun. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Nov. 07, 2017	Nov. 07, 2017	Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Dec. 31, 2026 USD ($)	Sep. 30, 2026 CAD ($)	Dec. 31, 2025 USD ($)	May 17, 2023 USD ($)
Commitments And Contingencies [Line Items]
Environmental liabilities		$ 51,000,000					$ 51,000,000				$ 55,000,000
Asset retirement obligations		57,000,000					57,000,000				$ 58,000,000
Surety bonds outstanding		171,000,000					171,000,000
Countervailing duty and Anti-dumping duty cash deposits on softwood lumber paid		831,000,000					831,000,000
Partial wind-up deficit within plans		106,000,000					$ 106,000,000			$ 150
Purchase of annuities to reconcile the pension deficits period							3 years
Forecast [Member]
Commitments And Contingencies [Line Items]
Estimated amount of contributions if annuities are purchased									$ 28,000,000
Countervailing Duties [Member]
Commitments And Contingencies [Line Items]
Percentage of preliminary determination countervailing duty rate on certain canadian softwood lumber imported to the US market						12.82%
Accumulated cash deposits paid							$ 558,000,000
Anti-dumping Duties [Member]
Commitments And Contingencies [Line Items]
Percentage of preliminary determination anti dumping rates on certain canadian softwood lumber imported to the US market					4.59%
Accumulated cash deposits paid							273,000,000
Pension Plans [Member]
Commitments And Contingencies [Line Items]
Provision for liability							0
Indemnification Guarantee [Member]
Commitments And Contingencies [Line Items]
Provision for liability							0
Standby Letters of Credit [Member]
Commitments And Contingencies [Line Items]
Surety bonds outstanding		82,000,000					82,000,000
Insurance Claims [Member]
Commitments And Contingencies [Line Items]
Loss contingency, direct costs recognized			$ 17,000,000	$ 4,000,000				$ 9,000,000
Gain (loss) on disposition of property, plant and equipment				2,000,000				2,000,000
Loss contingency, amount recovered		$ 17,000,000		$ 4,000,000				$ 11,000,000
Insurance Claims [Member] \| Owner [Member]
Commitments And Contingencies [Line Items]
Amount of excess warehouse damage							45,000,000
Insurance Claims [Member] \| Co-tenant [Member]
Commitments And Contingencies [Line Items]
Amount of excess warehouse damage							132,000,000
Climate Change and Air Quality Regulations [Member] \| Affordable Clean Energy [Member] \| Minimum [Member]
Commitments And Contingencies [Line Items]
Percentage of operating limit on retirement year	40.00%
Superfund Site [Member] \| Environmental Protection Agency [Member]
Commitments And Contingencies [Line Items]
Approximate total response costs identified in the notice of liability												$ 21,000,000
Provision for liability							$ 15,000,000