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Pension Plans and Postretirement Benefits - Target Allocation by Asset Class (Detail) - Pension Plan - UNITED STATES	Dec. 31, 2020
Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	49.00%
Equities
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	28.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Target allocation by asset class	23.00%

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+ References

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- Definition

Percentage of target 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/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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