Share-Based Compensation - Stock Options Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Awards granted
Share-based compensation expense (benefit) before taxes	$ 41.7	$ 21.1	$ 117.0	$ 22.5
Unrecognized compensation cost	62.0		$ 62.0
Stock Options with Performance Conditions
Awards granted
Granted (in shares)			500,000	400,000
Total grant date fair value			$ 50.2	$ 35.6
Share-based compensation expense (benefit) before taxes	7.2	5.2	19.1	6.4
Aggregate grant date fair value			$ 50.2	35.6
Stock options
Awards granted
Granted (in shares)			551,667
Total grant date fair value			$ 54.1	38.9
Share-based compensation expense (benefit) before taxes	$ 8.0	$ 6.0	$ 21.8	$ 12.5
Weighted average grant date fair value of stock options (in dollars per share)			$ 98.06	$ 85.39
Aggregate grant date fair value			$ 54.1	$ 38.9
Total grant date fair value of employee stock options that vested			$ 3.5	$ 54.9
Weighted average remaining vesting period			2 years 1 month 6 days