Stock-Based Compensation and Shareholders' Equity (Schedule of Assumptions for Option Pricing Model) (Details)	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011
Stock-Based Compensation And Shareholders' Equity [Abstract]
Risk-free interest rate	0.39%	1.84%
Dividend yield	4.68%	4.96%
Volatility	33.81%	30.04%
Expected life (years)	5.00	5.00

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Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

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- Definition

Description of the expected term under the specified contract (or assumed time period) the instrument will be outstanding before being exercised, placed into service or terminated, the reason and justification for its use, and the periods for which the method was used.

+ References

+ Details

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- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

+ Details

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- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

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