Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]
Common stock, par value	$ 1	$ 1
Common stock, authorized	300.0	300.0
Common stock, issued	93.4	93.4
Common stock, outstanding	86.6	86.5

Face amount or stated value per share of common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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

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-Number 210

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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