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Retirement Plans and Other Post-Retirement Benefits - Summary of Amounts Recognized in Consolidated Balance Sheets (Detail) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
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Pension Benefits [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Net amount recognized | $ 1.0 | $ 25.8
Other Benefits [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Net amount recognized | (9.2) | (9.7)
Other Assets [Member] | Pension Benefits [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Net amount recognized | 43.3 | 66.4
Current Liabilities [Member] | Pension Benefits [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Net amount recognized | (2.1) | (2.2)
Current Liabilities [Member] | Other Benefits [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Net amount recognized | (2.4) | (3.5)
Other Long-Term Liabilities [Member] | Pension Benefits [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Net amount recognized | (40.2) | (38.4)
Other Long-Term Liabilities [Member] | Other Benefits [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Net amount recognized | $ (6.8) | $ (6.2)

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- Definition Amount of asset (liability), recognized in statement of financial position, for defined benefit pension and other postretirement plans. + 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 (c) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109237824&loc=d3e1703-114919 + Details
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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 No definition available. + Details
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- Details
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