Summary of Significant Accounting Policies - Schedule of Changes in Restructuring Reserve (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 90.0	$ 13.2	$ 23.3
Severance costs	113.9	2.6
Other costs	35.3	1.0
Costs paid or utilized	72.4	13.7
Americas | United States
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	3.7	0.6	0.2
Severance costs	7.7	0.8
Office closure costs	4.6	0.4
Southern Europe | France
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	2.5	0.9	0.6
Severance costs	2.1
Other costs	0.4	0.9
Costs paid or utilized	0.9	0.6
Southern Europe | Italy
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	1.0	0.0	$ 0.3
Severance costs	1.6
Office closure costs	$ 0.6
Costs paid or utilized		$ 0.3