Restructuring Expenses and Repositioning Expenses Restructuring Expenses - Liability Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Reserve [Roll Forward]
Restructuring Reserve	$ 10.7	$ 6.7	$ 9.6	$ 7.6
Accruals for severance and other costs	10.1	11.4	17.8
Payments	$ (6.1)	(14.4)	(16.0)
Currency translation adjustments and other		$ 0.1	$ 0.2