Plan Assumptions (Detail)	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.27%	5.39%	5.88%
Rate of compensation increase	5.00%	5.00%	5.00%
Expected return on plan assets	8.25%	8.25%	8.50%
Discount rate	5.39%	5.88%	6.11%
Rate of compensation increase	5.00%	5.00%	5.00%
Expected return on plan assets	8.25%	8.25%	8.50%

Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Long Term Return on Assets

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- Definition

The interest rate used to adjust for the time value of money for the plan.

+ References

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

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- Definition

Expected rate of compensation increases (for pay-related plans).

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The interest rate used to adjust for the time value of money.

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- Definition

An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.

+ References

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

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-Glossary Expected Long-Term Rate of Return on Plan Assets

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Expected rate of compensation increases (for pay-related plans).

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