Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year, Deferral, American Rescue Plan Act

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- Definition

Defined Benefit Plan, Group Annuity Contract To Transfer Projected Benefit Obligations, Number Of Retirees

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- Definition

Defined Benefit Plan, Group Annuity Contract To Transfer Projected Benefit Obligations, Purchase Amount

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- Definition

Amount of contributions received and expected to be received by defined benefit plan from employer in current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4587-114921

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Amount of gain (loss) recognized in net periodic benefit (cost) credit from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk related to obligation and assets used to effect settlement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)(7)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=109237824&loc=SL108413299-114919

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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920

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- Definition

Amount of cash outflow for other postretirement benefit. Includes, but is not limited to, employer contribution to fund plan asset and payment to retiree. Excludes pension benefit.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
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Amount of cash outflow for pension benefit. Includes, but is not limited to, employer contribution to fund plan asset and payment to retiree. Excludes other postretirement benefit.

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Pension and Postretirement Benefits - Additional Information (Detail) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2021 USD ($) retiree	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash contributions, pension plans		$ 20.2	$ 325.6	$ 826.2
Cash contributions, postretirement benefits		21.6	327.7
Pension Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Settlement loss		158.0
Estimated cash contributions by the company for current fiscal year		50.3
Pension Plans \| U.S. Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Group annuity contract to transfer projected benefit obligations, purchase amount	$ 279.0
Group annuity contract to transfer projected benefit obligations, number of retirees \| retiree	11,600
Settlement loss		158.0
Previously-contemplated voluntary contribution no longer planning to make, American Rescue Plan		200.0
Postretirement Benefit Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated cash contributions by the company for current fiscal year		5.0
Cash contributions, postretirement benefits		$ 1.4	$ 2.1	$ 6.0