Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Tax expense (benefit)	$ 15.5	$ 6.0	$ 31.6	$ 18.5
Effective income tax rate	19.40%	9.90%	21.10%	16.20%
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax Cuts and Jobs Act of 2017, provisional income tax expense		$ 4.8		$ 4.5