Stock-Based Compensation - Schedule of Stock-Based Compensation Expense by Type of Award (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 17.7	$ 16.0	$ 17.5
Tax benefit from stock exercised and converted during the period	9.1	7.8	7.6
Non-qualified stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	4.5	3.6	4.0
Restricted stock, service based
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	6.4	6.1	6.4
Restricted stock, performance based
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	6.2	5.8	6.7
Employee stock purchase plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 0.6	$ 0.5	$ 0.4