Restructuring - Restructuring Costs by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 58.7	$ 24.5	$ 41.3
Water
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	23.6	10.5	17.4
Electrical
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	16.8	12.3	15.7
Other
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 18.3	$ 1.7	$ 8.2