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Employee Benefit Plans - Additional Information (Detail) $ in Millions | Jun. 30, 2018 USD ($)
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Defined Benefit Pension Plans |
Defined Benefit Plan Disclosure [Line Items] |
Expected contribution | $ 19.8
OPEB |
Defined Benefit Plan Disclosure [Line Items] |
Expected contribution | $ 1.0

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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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Namespace Prefix: | us-gaap_
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Balance Type: | na
Period Type: | duration

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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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920 + Details
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- Details
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- Details
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