Acquisitions and Discontinued Operations - Other Discontinued Operations Activity (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other businesses included in discontinued operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net loss recognized with disposition of business	$ 3.7	$ 4.4	$ 0.8

Amount after tax of an increase (decrease) to a gain (loss) previously reported in discontinued operations in a prior period.

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