| **CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)In Millions, except Share data, unless otherwise specified** | Jun. 30, 2013 | Dec. 31, 2012 |
|-----------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment                                        | $ 37.6        | $ 37.6        |
| Common stock, par value                                                                                                     |     |     |
| Common stock, shares authorized                                                                                             | 180,000,000   | 180,000,000   |
| Common stock, issued                                                                                                        | 92,314,092    | 92,302,299    |
| Common stock, outstanding                                                                                                   | 92,293,823    | 92,285,408    |
| Treasury stock, shares                                                                                                      | 20,269        | 16,891        |

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| - Definition
The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.
+ References
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| - Definition
Issuance value per share of no-par value common stock; generally not indicative of the fair market value per share.
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| - Definition
The maximum number of common shares permitted to be issued by an entity's charter and bylaws.
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| - Definition
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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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.
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| - Definition
Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.
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