Multiemployer Pension Plans (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 6,027	$ 6,125	$ 6,029
Central States, Southeast and Southwest Areas Pension Fund
Defined Benefit Plan Disclosure [Line Items]
EIN/Pension Plan Number	36-6044243/001
Pension Protection Act Zone Status	Red	Red
FIP / RP Status Pending / Implemented	Implemented
Contributions	1,724	1,848	1,775
Surcharge Imposed	No
Expiration Dates of Collective Bargaining Agreements, First	Apr. 30, 2013
Expiration Dates of Collective Bargaining Agreements	Dec. 31, 2013
Expiration Dates of Collective Bargaining Agreements, Last	Aug. 31, 2014
United Food and Commercial Workers Local One Pension Fund
Defined Benefit Plan Disclosure [Line Items]
EIN/Pension Plan Number	16-6144007/001
Pension Protection Act Zone Status	Red	Red
FIP / RP Status Pending / Implemented	Pending
Contributions	107	102	102
Surcharge Imposed	No
Expiration Dates of Collective Bargaining Agreements	Dec. 31, 2011
Pension Fund All Other
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 4,196	$ 4,175	$ 4,152

Entity Tax Identification and Plan Number

No definition available.

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- Definition

Indicate the multiemployer plan's certified zone status as currently required by the Pension Protection Act of 2006 or a subsequent amendment thereof. The zone status categories are red (critical status), orange (seriously endangered), yellow (endangered), and green (none of the above). The acceptable values are "red", "orange", "yellow", "green", "other", and "NA". A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

No definition available.

+ Details

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- Definition

Expiration date of the collective bargaining arrangement requiring contributions to the multiemployer plan, in CCYY-MM-DD format. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

No definition available.

+ Details

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- Definition

Expiration date of the collective bargaining arrangement requiring contributions to the multiemployer plan that will expire first in a group of associated collective bargaining arrangements, in CCYY-MM-DD format. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

No definition available.

+ Details

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- Definition

Expiration date of the collective bargaining arrangement requiring contributions to the multiemployer plan that will expire last in a group of associated collective bargaining arrangements, in CCYY-MM-DD format. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

No definition available.

+ Details

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- Definition

Indicate whether a funding improvement plan or rehabilitation plan has been implemented or is pending for a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. The acceptable values are "no", "pending", "implemented", "other", and "NA".

+ References

No definition available.

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- Definition

Indicate whether the employer paid a surcharge to the pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. The acceptable values are "no", "yes", and "NA".

+ References

No definition available.

+ Details

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- Definition

Amount of contributions made to multiemployer plans for each period for which a statement of income is presented. An employer may disclose total contributions to multiemployer plans without disaggregating the amounts attributable to pension plans and other postretirement benefit plans.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 12

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Section 50

-Paragraph 1

-SubTopic 80

-Topic 715

-URI http://asc.fasb.org/extlink&oid=6958064&loc=d3e29142-114947

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