Share-Based Compensation - Pre-Tax Compensation Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	$ 14.4	$ 13.9
Income tax benefit	(0.9)	(0.8)
Total share-based compensation expense, net of income taxes	13.5	13.1
Stock options expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	5.4	6.0
Restricted stock expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	2.0	1.6
Cash-settled restricted stock expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	1.9	1.1
Performance share units expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	$ 5.1	$ 5.2