Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Tax Expense (Benefit) [Line Items]
Effective income tax rate	15.50%	21.50%	19.20%	20.10%
Excess tax benefits (expense)		$ (1.9)		$ 5.4
Discrete tax expense (benefit) related to TCJA		1.7		(4.8)
Release of valuation allowances		1.2		7.3
Foreign accrual to return adjustment
Other Tax Expense (Benefit) [Line Items]
Other tax (benefit) expense		$ (2.0)		(2.0)
Gain on sale of business
Other Tax Expense (Benefit) [Line Items]
Other tax (benefit) expense				42.0
Tax accounting method change
Other Tax Expense (Benefit) [Line Items]
Other tax (benefit) expense				$ (8.0)