Restructuring and other - Restructuring and Other Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring and other	$ 7.8	$ 13.8	$ 18.1	$ 20.7
Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other	1.7	4.1	4.4	8.9
Acquisitions and related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other	4.0	1.5	8.2	1.5
Restructuring, integration and other
Restructuring Cost and Reserve [Line Items]
Restructuring and other	$ 2.1	$ 8.2	$ 5.5	$ 10.3