Goodwill and Other Intangible Assets (Pro Forma Financial Information and Acquisition Results) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Pro Forma Financial Information and Acquisition Results [Abstract]
Business combinations, unaudited supplemental pro forma revenue	$ 2,000.0	$ 1,900.0	$ 4,000.0	$ 3,600.0
Business combinations, unaudited supplemental pro forma net income (loss)	81.6	58.6	151.2	95.5
Business combinations, consolidated acquisition-related revenue	271.4	63.5	358.2	113.0
Business combinations, consolidated acquisition-related income (loss)	$ 3.5	$ 0.4	$ 4.7	$ (0.5)

No definition available.

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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-Publisher FASB
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- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
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This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

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