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Acquisitions Business Combinations Additional Information (Details) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Acquired Indefinite-lived Intangible Assets [Line Items] |  |  |
Payments to Acquire Businesses, Net of Cash Acquired | $ 224.4 | $ 151.5 |
Asset Acquisition, Consideration Transferred, Contingent Consideration | 34.0 |  |
Asset Acquisition, Contingent Consideration, Liability | $ 15.3 |  |
2020 Acquisitions |  |  |
Acquired Indefinite-lived Intangible Assets [Line Items] |  |  |
Goodwill, Acquired During Period |  |  | $ 129.5
Business Acquisition, Goodwill, Expected Tax Deductible Amount |  |  | $ 77.1

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- Definition Amount of contingent consideration recognized as part of consideration transferred in asset acquisition. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 50 -Section 30 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=123362884&loc=d3e9212-128498 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 50 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=123385561&loc=d3e9135-128495 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 50 -Section 30 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=123362884&loc=d3e9215-128498 + Details
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