Earnings Per Share (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Weighted-average shares:
Common shares outstanding	70,349,265	72,950,361	71,248,765	75,791,005
Restricted common shares	571,326	970,559	596,749	965,655
Total Weighted Average Shares	70,920,591	73,920,920	71,845,514	76,756,660
Percentage of weighted-average shares:
Common shares outstanding	99.19%	98.69%	99.17%	98.74%
Restricted common shares	0.81%	1.31%	0.83%	1.26%
Total	100.00%	100.00%	100.00%	100.00%

This element represents nonvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid). Basic and dilutive earnings per share are generally disclosed for such shares using the two-class method.

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+ Details

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

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