Retirement Benefits - Benefits Expected to Be Paid from Pension and Other Postretirement Benefit Plans, Which Reflect Future Years of Services (Detail) $ in Thousands	Dec. 31, 2019 USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2020	$ 42,916
2021	42,716
2022	43,807
2023	44,882
2024	45,793
2025-2029	237,935
Defined Benefit Plan Expected Future Benefit Payments	458,049
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2020	1,798
2021	1,671
2022	1,527
2023	1,466
2024	1,416
2025-2029	6,463
Defined Benefit Plan Expected Future Benefit Payments	$ 14,341

Defined Benefit Plan, Expected Future Benefit Payments

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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.

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- Definition

Amount of benefits for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following latest fiscal year.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920

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- Definition

Amount of benefits for defined benefit plan expected to be paid in next fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in fifth fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in fourth fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in third fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in second fiscal year following latest fiscal year.

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