Fair Value Measurements - Fair Value of Contingent Consideration Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in fair value	$ (50.7)	$ (86.3)	$ (63.7)
Fair value, measurements, recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of year	259.8	346.1
Changes in fair value	(50.7)	(86.3)
Fair value, end of year	$ 209.1	$ 259.8	$ 346.1