Earnings Per Share (EPS) (Details) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Weighted-average number of basic shares	303.9	324.8	324.7
Shares issuable under incentive stock plans	3.7	3.8	5.1
Exchangeable Senior Notes	3.0	10.7	10.0
Weighted-average number of diluted shares	310.6	339.3	339.8
Anti-dilutive shares	5.2	5.0	12.4
Exchangeable Senior Notes [Member]
Shares issued for settlement of Exchangeable Senior Notes	10.8

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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-URI http://asc.fasb.org/extlink&oid=6510752

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-Name Accounting Standards Codification

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-Publisher FASB

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+ Details

- Definition

Number of shares issued during the period as a result of the conversion of convertible securities.

+ References

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

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-Name Regulation S-X (SX)

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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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-Publisher FASB

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

+ Details