Restructuring Costs and Other - By Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 7.4	$ 0.0	$ 10.4	$ 0.7
Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	6.5	0.4	7.2	1.2
Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.9	(0.4)	3.2	(0.5)
Electrical
Restructuring Cost and Reserve [Line Items]
Restructuring charges	6.3	0.0	7.4	0.7
Electrical | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	5.5	0.3	5.7	1.1
Electrical | Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0.8	(0.3)	1.7	(0.4)
Power
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.1	0.0	3.0	0.0
Power | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.0	0.1	1.5	0.1
Power | Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 0.1	$ (0.1)	$ 1.5	$ (0.1)