Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Effective income tax rate	21.80%	30.40%	22.80%	29.00%
Federal statutory tax rate			21.00%	35.00%
Tax cuts and jobs act of 2017 incomplete accounting current income tax expense	$ 3.1
Tax cuts and jobs act of 2017 incomplete accounting undistributed foreign subsidiary earnings and profits subject to deemed mandatory repatriation, reduction in estimated taxes	2.6
Tax benefit to provisional estimate for reduction in corporate tax rate applied to deferred tax assets	$ 0.5
Income Taxes Paid			$ 20.2	$ 10.9