Stock-Based Compensation - Schedule of Stock-Based Compensation Expense by Type of Award (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 16.1	$ 17.9	$ 17.2
Tax benefit from stock exercised and converted during the period	2.8	9.2	5.8
Non-qualified stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	3.6	3.3	3.6
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	5.8	6.4	6.0
PRSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	6.3	7.9	7.4
Employee stock purchase plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 0.4	$ 0.3	$ 0.2