| **Cash and Marketable Securities - Tables 1 & 2 (Details) (USD $)In Millions, unless otherwise specified** | Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009 | Dec. 31, 2008 |
|----------------------------------------------------------------------------------------------------------------|---------------|---------------|---------------|---------------|
| **Components of Investments**                                                                                  |          |          |          |          |
| Cash and cash equivalents                                                                                      | $ 30.1        | $ 48.3        | $ 80.7        | $ 31.7        |
| Restricted Cash                                                                                                | 35.3          | 36.5          |          |          |
| Restricted Marketable Securities                                                                               | 45.2          | 37.5          |          |          |
| Total                                                                                                          | 110.6         | 122.3         |          |          |
| Cash [Member]                                                                                                  |          |          |          |          |
| **Components of Investments**                                                                                  |          |          |          |          |
| Cash and cash equivalents                                                                                      | 30.1          | 48.3          |          |          |
| Restricted Cash                                                                                                | 35.3          | 36.5          |          |          |
| Restricted Marketable Securities                                                                               | 0             | 0             |          |          |
| Total                                                                                                          | 65.4          | 84.8          |          |          |
| Equity Securities [Member]                                                                                     |          |          |          |          |
| **Components of Investments**                                                                                  |          |          |          |          |
| Cash and cash equivalents                                                                                      | 0             | 0             |          |          |
| Restricted Cash                                                                                                | 0             | 0             |          |          |
| Restricted Marketable Securities                                                                               | 45.2          | 37.5          |          |          |
| Total                                                                                                          | $ 45.2        | $ 37.5        |          |          |

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| - Definition
Total investments of the Company which includes cash, cash equivalents, restricted cash, and marketable securities.
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No definition available.
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| - Definition
Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).
+ References
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| - Definition
Total debt and equity financial instruments including: (1) securities held-to-maturity, (2) trading securities, and (3) securities available-for-sale that are pledged to one or more secured parties who have the right to buy, sell, or re-pledge the collateral.
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| - Definition
The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations.
+ References
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