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Equity Method Investments in Affiliates - Change in Equity Method Investments (Details) - USD ($) $ in Millions | 9 Months Ended
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Sep. 30, 2018 | Sep. 30, 2017
Change in Equity Method Investments in Affiliates [Roll Forward] |  |
Balance, as of December 31, 2017 | $ 3,304.7 |
Distributions of earnings from equity method investments | (410.3) | $ (368.0)
Balance, as of September 30, 2018 | 3,055.3 |
Equity Method Investee |  |
Change in Equity Method Investments in Affiliates [Roll Forward] |  |
Balance, as of December 31, 2017 | 3,304.7 |
Equity method earnings | 300.3 |
Equity method intangible amortization and impairments | (109.0) |
Distributions of earnings from equity method investments | (410.3) |
Foreign currency translation | (21.3) |
Other | (9.1) |
Balance, as of September 30, 2018 | $ 3,055.3 |

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