Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Other Tax Expense (Benefit) [Line Items]
Effective income tax rate	18.20%	21.50%	21.20%	19.70%
Release of valuation allowances		$ 8.5		$ 8.5
Gain on sale of business
Other Tax Expense (Benefit) [Line Items]
Other tax expense (benefit)		42.0		42.0
Tax accounting method change
Other Tax Expense (Benefit) [Line Items]
Other tax expense (benefit)		$ 8.0		$ 8.0