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Fair Value Measurements - Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Financial Liabilities
Contingent payment obligations	$ 14.7
Fair Value Measured on a Recurring Basis
Financial Assets
Investments in equity securities	37.9	$ 447.9
Investments in debt securities	423.1	269.0
Financial Liabilities
Contingent payment obligations	14.7	21.0
Affiliate equity purchase obligations	53.9	24.5
Fair Value Measured on a Recurring Basis | Level 1
Financial Assets
Investments in equity securities	37.9	305.6
Investments in debt securities	0.0	0.0
Financial Liabilities
Contingent payment obligations	0.0	0.0
Affiliate equity purchase obligations	0.0	0.0
Fair Value Measured on a Recurring Basis | Level 2
Financial Assets
Investments in equity securities	0.0	142.3
Investments in debt securities	423.1	269.0
Financial Liabilities
Contingent payment obligations	0.0	0.0
Affiliate equity purchase obligations	0.0	0.0
Fair Value Measured on a Recurring Basis | Level 3
Financial Assets
Investments in equity securities	0.0	0.0
Investments in debt securities	0.0	0.0
Financial Liabilities
Contingent payment obligations	14.7	21.0
Affiliate equity purchase obligations	$ 53.9	$ 24.5

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481830/320-10-45-1

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