Earnings Per Share (Details) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Anti-dilutive shares not included in diluted common share outstanding (in shares)		0.9
Weighted-average basic common shares outstanding (in shares)	179.3	177.7	179.1	177.6
Potential number of shares issuable upon excerise of in-the-money stock options under the Long-term Stock Incentive Plan	0.2	0	0.3	0.9
Average diluted common shares outstanding (in shares)	179.5	177.7	179.4	178.5

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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+ Details

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References+ 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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-URI http://asc.fasb.org/extlink&oid=6528421

+ Details