| **Investments in and Advances to Nonconsolidated Affiliates (Tables)**                                | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
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| **Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| Schedule of Combined Results of Operations of Equity Method Affiliates                                | The following summarizes the combined results of operations of our equity method affiliates (on a 100% basis, in millions): Three Months Ended September 30, Nine Months Ended September 30, 2014 2013 2014 2013Net operating revenues$7.8 $16.2 $44.1 $55.4Operating expenses(3.3) (10.3) (22.7) (32.5)Income from continuing operations, net of tax4.2 4.4 28.2 18.4Net income4.2 4.4 28.2 18.4 |

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| - Definition
Tabular disclosure of the combined results of operations of our equity method affiliates (on a 100% basis) for the periods presented.
+ References
No definition available.
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