Fair Value Measurements - Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Financial Assets
Fair value	$ 34.8	$ 32.3
Investments in debt securities	50.0	24.3
Financial Liabilities
Contingent payment obligations	0.0	5.7
Affiliate equity purchase obligations	161.2	54.8
Level 1
Financial Assets
Fair value	34.8	32.3
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
Level 2
Financial Assets
Fair value	0.0	0.0
Investments in debt securities	50.0	24.3
Financial Liabilities
Contingent payment obligations	0.0	0.0
Affiliate equity purchase obligations	0.0	0.0
Level 3
Financial Assets
Fair value	0.0	0.0
Investments in debt securities	0.0	0.0
Financial Liabilities
Contingent payment obligations	0.0	5.7
Affiliate equity purchase obligations	$ 161.2	$ 54.8