| **Redeemable Noncontrolling Interests - Table 1 (Details) - USD ($) $ in Millions** | 3 Months Ended | 9 Months Ended |
|-------------------------------------------------------------------------------------|----------------|----------------|
||
| **Redeemable Noncontrolling Interest [Line Items]**                                 |           |           |   |   |
| Balance at beginning of period                                                      |           |           | $ 121.1 |   |
| Net income attributable to noncontrolling interests                                 | $ 3.7          | $ 3.7          | 11.2 | $ 10.1 |
| Distributions declared                                                              |           |           | (43.1) | (36.7) |
| Change in fair value                                                                |           |           | 10.2 | (14.9) |
| Balance at end of period                                                            | 109.4          |           | 109.4 |   |
| Redeemable Noncontrolling Interest [Member]                                         |           |           |   |   |
| **Redeemable Noncontrolling Interest [Line Items]**                                 |           |           |   |   |
| Balance at beginning of period                                                      |           |           | 121.1 | 84.7 |
| Net income attributable to noncontrolling interests                                 |           |           | 11.2 | 10.1 |
| Distributions declared                                                              |           |           | (6.4) | (5.6) |
| Change in fair value                                                                |           |           | (16.5) | 24.9 |
| Balance at end of period                                                            | $ 109.4        | $ 114.1        | $ 109.4 | $ 114.1 |

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| - Definition
Change in noncontrolling interest during the period as a result of a change in the redemption value of redeemable noncontrolling interest.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
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