Fair Value Measurements - Changes in Level 3 Liabilities (Details) - Significant Unobservable Inputs (Level 3) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Contingent Payment Obligations
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 0.0	$ 5.7
Purchases and issuances	0.0	0.0
Settlements and reductions	0.0	0.0
Net realized and unrealized (gains) losses	0.0	(0.1)
Balance, end of period	0.0	5.6
Net change in unrealized (gains) losses relating to instruments still held at the reporting date	0.0	(0.1)
Affiliate Equity Purchase Obligations
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	161.2	54.8
Purchases and issuances	32.0	22.0
Settlements and reductions	(33.9)	(29.7)
Net realized and unrealized (gains) losses	34.9	1.3
Balance, end of period	194.2	48.4
Net change in unrealized (gains) losses relating to instruments still held at the reporting date	$ 34.9	$ 1.3