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Pension Plans and Postretirement Benefits - Plan Asset Allocations by Asset Category (Detail)	Dec. 31, 2023	Dec. 31, 2022
United States: | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Total	100.00%	100.00%
United States: | Pension Plan | U.S. Government Securities
Defined Benefit Plan Disclosure [Line Items]
Total	34.00%	36.00%
United States: | Pension Plan | Commingled and Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Total	25.00%	25.00%
United States: | Pension Plan | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Total	15.00%	16.00%
United States: | Pension Plan | Diversified Credit
Defined Benefit Plan Disclosure [Line Items]
Total	13.00%	13.00%
United States: | Pension Plan | Fixed Income (excluding U.S. Government Securities)
Defined Benefit Plan Disclosure [Line Items]
Total	6.00%	5.00%
United States: | Pension Plan | Partnerships with Security Holdings
Defined Benefit Plan Disclosure [Line Items]
Total	2.00%	3.00%
United States: | Pension Plan | Other
Defined Benefit Plan Disclosure [Line Items]
Total	5.00%	2.00%
Canada | Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Total	100.00%	100.00%
Canada | Other Benefits | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Total	61.00%	51.00%
Canada | Other Benefits | Equity Securities and Commingled Mutual Funds
Defined Benefit Plan Disclosure [Line Items]
Total	35.00%	29.00%
Canada | Other Benefits | Other
Defined Benefit Plan Disclosure [Line Items]
Total	4.00%	20.00%

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- Definition

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+ References

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- Definition

Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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