| **Fair Value Measurements - Table 1 (Details) (Restricted Marketable Securities [Member], USD $)In Millions, unless otherwise specified** | 6 Months Ended | 12 Months Ended |
|-------------------------------------------------------------------------------------------------------------------------------------------|----------------|-----------------|
||
| Other Current Assets [Member]                                                                                                             |           |            |
| **Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]**                                                             |           |            |
| Restricted Marketable Securities, Fair Value                                                                                              | $ 5.5          | $ 4.7           |
| Fair Value Measurements, Valuation Techniques                                                                                             | M              | M               |
| Other Current Assets [Member] | Fair Value, Inputs, Level 1 [Member]                                                                      |           |            |
| **Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]**                                                             |           |            |
| Restricted Marketable Securities, Fair Value                                                                                              | 0              | 0               |
| Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member]                                                                      |           |            |
| **Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]**                                                             |           |            |
| Restricted Marketable Securities, Fair Value                                                                                              | 5.5            | 4.7             |
| Other Current Assets [Member] | Fair Value, Inputs, Level 3 [Member]                                                                      |           |            |
| **Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]**                                                             |           |            |
| Restricted Marketable Securities, Fair Value                                                                                              | 0              | 0               |
| Other Long-term Assets [Member]                                                                                                           |           |            |
| **Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]**                                                             |           |            |
| Restricted Marketable Securities, Fair Value                                                                                              | 44.4           | 42.9            |
| Fair Value Measurements, Valuation Techniques                                                                                             | M              | M               |
| Other Long-term Assets [Member] | Fair Value, Inputs, Level 1 [Member]                                                                    |           |            |
| **Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]**                                                             |           |            |
| Restricted Marketable Securities, Fair Value                                                                                              | 0              | 0               |
| Other Long-term Assets [Member] | Fair Value, Inputs, Level 2 [Member]                                                                    |           |            |
| **Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]**                                                             |           |            |
| Restricted Marketable Securities, Fair Value                                                                                              | 44.4           | 42.9            |
| Other Long-term Assets [Member] | Fair Value, Inputs, Level 3 [Member]                                                                    |           |            |
| **Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]**                                                             |           |            |
| Restricted Marketable Securities, Fair Value                                                                                              | $ 0            | $ 0             |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.
+ References
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| X                                                                                                                                                                                                 |
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Description of the inputs and valuation technique(s) used to measure fair value.
+ References
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