Restructuring Costs and Other - By Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 5.2	$ 2.4	$ 15.6	$ 3.1
Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4.0	1.0	11.3	2.2
Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.2	1.4	4.3	0.9
Electrical
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4.1	1.4	11.4	2.1
Electrical | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2.7	0.9	8.4	2.0
Electrical | Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.4	0.5	3.0	0.1
Power
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.1	1.0	4.2	1.0
Power | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1.3	0.1	2.9	0.2
Power | Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ (0.2)	$ 0.9	$ 1.3	$ 0.8