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Investments in Marketable Securities (Tables) | 9 Months Ended
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Sep. 30, 2021
Marketable Securities [Abstract] |
Schedule of Investments in Marketable Securities | The following table summarizes the cost, gross unrealized gains, gross unrealized losses, and fair value of Investments in marketable securities:
|  |  |  |  | December 31, 2020 |  | September 30, 2021
Cost |  |  |  |  | $ | 69.4 |  |  | $ | 68.5 |
Unrealized gains |  |  |  |  | 5.5 |  |  | 8.2 |
Unrealized losses |  |  |  |  | (0.0 | ) |  | (0.9) |
Fair value |  |  |  |  | $ | 74.9 |  |  | $ | 75.8 |

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- Definition Tabular disclosure of marketable securities. This may consist of investments in certain debt and equity securities, short-term investments and other assets. + References No definition available. + Details
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