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Fair Value Measurements - Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Financial Liabilities
Contingent payment obligations	$ 22.9
Fair Value Measured on a Recurring Basis
Financial Assets
Investments in equity securities	186.5	$ 447.9
Investments in debt securities	271.2	269.0
Derivative financial instruments	0.9	0.5
Financial Liabilities
Contingent payment obligations	22.9	21.0
Affiliate equity purchase obligations	60.9	24.5
Derivative financial instruments	1.1	0.9
Fair Value Measured on a Recurring Basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets
Investments in equity securities	45.0	305.6
Investments in debt securities	0.0	0.0
Derivative financial instruments	0.0	0.0
Financial Liabilities
Contingent payment obligations	0.0	0.0
Affiliate equity purchase obligations	0.0	0.0
Derivative financial instruments	0.0	0.0
Fair Value Measured on a Recurring Basis | Significant Other Observable Inputs (Level 2)
Financial Assets
Investments in equity securities	141.5	142.3
Investments in debt securities	271.2	269.0
Derivative financial instruments	0.9	0.5
Financial Liabilities
Contingent payment obligations	0.0	0.0
Affiliate equity purchase obligations	0.0	0.0
Derivative financial instruments	1.1	0.9
Fair Value Measured on a Recurring Basis | Significant Unobservable Inputs (Level 3)
Financial Assets
Investments in equity securities	0.0	0.0
Investments in debt securities	0.0	0.0
Derivative financial instruments	0.0	0.0
Financial Liabilities
Contingent payment obligations	22.9	21.0
Affiliate equity purchase obligations	60.9	24.5
Derivative financial instruments	$ 0.0	$ 0.0

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