Income Taxes (Schedule of Income/(Loss) Before (Benefit)/Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Examination [Line Items]
Income from continuing operations before (benefit) / provision for income taxes	$ 191.6	$ 20.9	$ 186.0
U.S. operations
Income Tax Examination [Line Items]
Income from continuing operations before (benefit) / provision for income taxes	251.9	157.5	227.6
Non-U.S. operations
Income Tax Examination [Line Items]
Income from continuing operations before (benefit) / provision for income taxes	$ (60.3)	$ (136.6)	$ (41.6)