Pension and Other Post-Retirement Benefits - Additional Information (Detail)	9 Months Ended
Sep. 30, 2015 USD ($)
Post-Retirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected contribution to defined benefit plan	$ 1,300,000
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected contribution to defined benefit plan	$ 0

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.

No definition available.

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