Restructuring - Restructuring Reserve Activity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring and Related Activities [Abstract]
Balance at January 1			$ 54.0	$ 89.9
Liabilities incurred	$ 2.2	$ 14.4	6.1	27.3
Liabilities paid/settled			(23.2)	(37.7)
Balance at June 30	$ 36.9	$ 79.5	$ 36.9	$ 79.5