Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Dec. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Taxes [Abstract]
Effective tax rate		25.40%	31.10%
Income tax expense reduction, resolution of foreign tax claims and reduction of income tax applied against overall foreign earnings		$ 19.0
Net Income Tax Benefit of Net Gain on Disposition of Subsidiaries and Repositioning Actions		(25.0)
Impact of Tax Act	$ 106.3	28.9	$ 0.0
Unrecognized tax benefits		153.2
Unrecognized tax benefits that would impact effective tax rate		$ 140.2