Pension and Postretirement Benefits - Additional Information (Detail) (USD $)	6 Months Ended
Jun. 30, 2013
Funded Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Amount expected to contribute in funded pension plans	$ 2,700,000
Amount contributed in pension plans	1,000,000
Unfunded Pension Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Amount contributed in pension plans	537,000
Amount expected to contribute in unfunded pension plans	1,800,000
Postretirement Benefit Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Amount expected to contribute in postretirement benefit plans	400,000
Amount contributed in postretirement benefit plans	$ 42,000

Defined benefit funded pension plan estimated future employer contributions in current fiscal year.

No definition available.

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- Definition

Defined benefit unfunded pension plan estimated future employer contributions in current fiscal year.

+ References

No definition available.

+ Details

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- Details

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Period Type:	duration

- 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_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of cash or cash equivalents contributed during the reporting period by the entity to fund its pension plans and its non-pension postretirement benefit plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

+ Details

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- Definition

The amount of cash or cash equivalents contributed by the entity to fund its pension plans.

+ References

+ Details

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