| **Assets Held for Sale and Results of Discontinued Operations (Tables)**            | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
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| **Assets Held for Sale and Results of Discontinued Operations (Tables) [Abstract]** | Â                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
| Operating results of discontinued operations                                        |      The operating results of discontinued operations are as follows (in millions):                      **Three Months Ended**  **Six Months Ended**   **June 30,**  **June 30,**   **2011**  **2010**  **2011**  **2010** Net operating revenues    $29.5  $30.1  $86.5  $63.4 Costs and expenses     26.3   27.3   54.5   58.0 Impairments     —   —   1.3   0.6                 Income from discontinued operations     3.2   2.8   30.7   4.8 Loss on disposal of assets of   discontinued operations     —   (0.3)  —   (1.2)Income tax (expense) benefit     (1.6)  0.8   (11.6)  1.0                 Income from discontinued operations,   net of tax    $1.6  $3.3  $19.1  $4.6                                                                                                                                                                                  |
| Assets and Liabilities Held For Sale                                                |      Assets and liabilities held for sale consist of the following (in millions):              **As of**  **As of**   **June 30,**  **December 31,**   **2011**  **2010** Assets:           Accounts receivable, net    $16.8  $18.2 Other current assets     1.3   1.6           Total current assets     18.1   19.8           Property and equipment, net     44.3   46.4 Goodwill     11.0   11.0 Long-term assets     0.4   0.4           Total long-term assets     55.7   57.8           Total assets    $73.8  $77.6           Liabilities:           Accounts payable    $3.8  $4.5 Accrued expenses and other current liabilities     6.8   7.0           Total current liabilities     10.6   11.5 Long-term liabilities     1.0   1.2           Total liabilities    $11.6  $12.7            |

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| - Definition
Tabular disclosure of assets and liabilities held for sale as of the balance sheet date.
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| - Definition
Assets Held for Sale and Results of Discontinued Operations.
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| - Definition
Tabular disclosure of operating results of discontinued operations for the periods presented.
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