Share-Based Compensation - Pre-Tax Compensation Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	$ 5.2	$ 2.5	$ 23.7	$ 21.1
Income tax benefit	(0.7)	(0.5)	(2.3)	(2.1)
Total share-based compensation expense, net of income taxes	4.5	2.0	21.4	19.0
Stock options expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	1.5	1.1	8.4	8.7
Restricted stock expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	1.6	1.1	5.7	4.4
Cash-settled restricted stock expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	1.2	0.6	2.8	2.3
Performance share units expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total pre-tax share-based compensation expense	$ 0.9	(0.3)	$ 6.8	5.7
Executive forfeitures		$ 1.1		$ 1.1