Stock-Based Compensation - Schedule of Stock-Based Compensation Expense by Type of Award (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 14.7	$ 17.7	$ 16.0
Tax benefit from stock exercised and converted during the period	4.5	9.1	7.8
Non-qualified stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	6.8	4.5	3.6
Restricted stock, service based (“RSUs”)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	8.4	6.4	6.1
Restricted stock, performance based (“PRSUs”)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	(0.7)	6.2	5.8
Employee stock purchase plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 0.2	$ 0.6	$ 0.5