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Benefit Plans - Additional Information (Detail) $ in Millions | 3 Months Ended
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Mar. 31, 2017 USD ($)
Defined Benefit Plan Disclosure [Line Items] |
Number of highest-paid consecutive years for benefits | 5 years
Defined Benefit Pension Plan [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Minimum eligibility for full-time employees, age | 21 years
Amount contributed to pension plan, Expected in future | $ 2.1
Defined Benefit Pension Plan [Member] | Minimum [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Period of service credit by employee | 1 year

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- Definition Defined benefit pension plan minimum eligible age of employee. + References No definition available. + Details
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Balance Type: | na
Period Type: | duration

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- Definition Number of highest paid consecutive periods of service for calculation of average compensation related to benefits. + References No definition available. + Details
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Period Type: | duration

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- Definition Period of service credit by employee. + References No definition available. + 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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- Definition Amount of employer's best estimate of contributions expected to be paid to the plan in the current remaining fiscal period. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
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- Details
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Namespace Prefix: |
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X
- Details
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Namespace Prefix: |
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Balance Type: |
Period Type: |