Share-based Compensation - Components of Share-Based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award
Related tax benefit (expense)	$ 3.3	$ 1.8	$ (0.6)
2017 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award
Share-based compensation expense (benefit)	13.3	7.3	(2.3)
Restricted Shares and RSUs
Share-based Compensation Arrangement by Share-based Payment Award
Share-based compensation expense (benefit)	5.8	4.5	3.2
Performance Shares and PSUs
Share-based Compensation Arrangement by Share-based Payment Award
Share-based compensation expense (benefit)	6.1	1.9	(6.0)
Non-Qualified Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Share-based compensation expense (benefit)	$ 1.4	$ 0.9	$ 0.5