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Retirement Plans - Defined Benefit Plan, Actual Plan Asset Allocation (Detail)	Dec. 31, 2020	Dec. 31, 2019
United States [Member] | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	100.00%	100.00%
United States [Member] | Equity Securities | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	67.00%	64.00%
United States [Member] | Debt Securities [Member] | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	33.00%	36.00%
United States [Member] | Cash and Cash Equivalents [Member] | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	0.00%	0.00%
United States [Member] | Insurance Contracts And Other [Member] | Retiree Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	0.00%	0.00%
Non-U.S. Pension Plans [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	100.00%	100.00%
Non-U.S. Pension Plans [Member] | Equity Securities | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	5.00%	6.00%
Non-U.S. Pension Plans [Member] | Debt Securities [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	20.00%	21.00%
Non-U.S. Pension Plans [Member] | Cash and Cash Equivalents [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	1.00%	1.00%
Non-U.S. Pension Plans [Member] | Insurance Contracts And Other [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Total defined benefit plan asset allocation	74.00%	72.00%

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ 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
-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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