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Goodwill and Other Intangible Assets - Schedule of Goodwill and Other Intangible Assets Rollforward (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Goodwill |  |  |
Goodwill, beginning balance | $ 168.8 | $ 176.5 |
Acquisitions of businesses | 270.4 | 0.0 |
Finite-Lived Intangible Assets Acquired | 0.3 | 0.0 |
Dispositions | 0.0 | (6.7) |
Measurement period adjustments | 0.0 | (1.0) |
Goodwill, ending balance | 439.2 | 168.8 | $ 176.5
Other Intangible Assets |  |  |
Other intangible assets (excluding goodwill), beginning balance | 201.8 | 215.9 |
Acquisition of businesses | 101.0 | 0.0 |
Dispositions of businesses | 0.0 | (6.9) |
Amortization | (22.0) | (7.2) | (5.2)
Other intangible assets (excluding goodwill), ending balance | 281.1 | 201.8 | 215.9
Total Goodwill and Other Intangible Assets |  |  |
Total Goodwill and Other Intangible Assets, beginning balance | 370.6 | 392.4 |
Acquisition of businesses | 371.4 | 0.0 |
Acquisition of intangible assets | 0.3 | 0.0 |
Disposition of businesses | 0.0 | (13.6) |
Measurement period adjustments | 0.0 | (1.0) |
Amortization | (22.0) | (7.2) | (5.2)
Total Goodwill and Other Intangible Assets, ending balance | $ 720.3 | $ 370.6 | $ 392.4

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- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 40 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482640/350-30-55-40 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482686/350-30-45-2 + Details
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- Definition Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482686/350-30-45-1 + Details
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