Supplementary Data Other (Expense) Income, Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other Income and Expenses [Abstract]
Net (losses) gains on sales of businesses	$ (24.4)	$ 0.9
Other	0.0	(0.1)
Total other (expense) income, net	$ (24.4)	$ 0.8