Restructuring Costs and Other - By Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 5.5	$ 5.8
Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4.2	1.8
Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.3	4.0
Electrical
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4.7	5.5
Electrical | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3.7	1.8
Electrical | Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.0	3.7
Power
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.8	0.3
Power | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.5	0.0
Power | Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 0.3	$ 0.3