Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Tax expense (benefit)	$ 10.9	$ 8.0	$ 42.5	$ 26.5
Effective income tax rate	16.80%	13.10%	19.80%	15.10%
Other Income Tax Expense (Benefit), Continuing Operations	$ 1.0		$ 1.0
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax Cuts and Jobs Act of 2017, provisional income tax expense		$ (0.4)		$ 4.1