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Goodwill and Other Intangible Assets - Schedule of Goodwill by Segment (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Goodwill [Roll Forward] |  |
Beginning balance | $ 2,479.6 | $ 2,455.0
Foreign currency translation | (16.8) | 24.6
Ending balance | 2,462.8 | 2,479.6
Corporate |  |
Goodwill [Roll Forward] |  |
Beginning balance | 1,074.1 | 1,074.1
Foreign currency translation | 0.0 | 0.0
Ending balance | 1,074.1 | 1,074.1
Accumulated impairment losses | 1,571.0 |
Small Business |  |
Goodwill [Roll Forward] |  |
Beginning balance | 185.9 | 185.9
Foreign currency translation | 0.0 | 0.0
Ending balance | 185.9 | 185.9
Public |  |
Goodwill [Roll Forward] |  |
Beginning balance | 929.6 | 929.6
Foreign currency translation | 0.0 | 0.0
Ending balance | 929.6 | 929.6
Accumulated impairment losses | 354.0 |
Other |  |
Goodwill [Roll Forward] |  |
Beginning balance | 290.0 | 265.4
Foreign currency translation | (16.8) | 24.6
Ending balance | 273.2 | $ 290.0
Accumulated impairment losses | $ 28.0 |

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