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Fair Value Measurements - Assets and Liabilities Measured on a Recurring Basis (Details) - Fair Value Measured on a Recurring Basis - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Financial Assets
Investments in marketable securities	$ 81.1	$ 78.5
Derivative financial instruments	1.0	0.9
Financial Liabilities
Contingent payment obligations	31.4	40.3
Affiliate equity purchase obligations	47.6	12.6
Derivative financial instruments	0.9	0.8
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets
Investments in marketable securities	68.2	64.5
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
Significant Other Observable Inputs (Level 2)
Financial Assets
Investments in marketable securities	12.9	14.0
Derivative financial instruments	1.0	0.9
Financial Liabilities
Contingent payment obligations	0.0	0.0
Affiliate equity purchase obligations	0.0	0.0
Derivative financial instruments	0.9	0.8
Significant Unobservable Inputs (Level 3)
Financial Assets
Investments in marketable securities	0.0	0.0
Derivative financial instruments	0.0	0.0
Financial Liabilities
Contingent payment obligations	31.4	40.3
Affiliate equity purchase obligations	47.6	12.6
Derivative financial instruments	$ 0.0	$ 0.0

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