Restructuring Costs - By Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Restructuring Cost and Reserve [Line Items]
Pre-tax Restructuring Costs	$ 5.8	$ 2.7
Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Pre-tax Restructuring Costs	1.8	2.6
Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Pre-tax Restructuring Costs	4.0	0.1
Electrical
Restructuring Cost and Reserve [Line Items]
Pre-tax Restructuring Costs	5.5	2.0
Electrical | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Pre-tax Restructuring Costs	1.8	1.9
Electrical | Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Pre-tax Restructuring Costs	3.7	0.1
Power
Restructuring Cost and Reserve [Line Items]
Pre-tax Restructuring Costs	0.3	0.7
Power | Cost of goods sold
Restructuring Cost and Reserve [Line Items]
Pre-tax Restructuring Costs	0.0	0.7
Power | Selling & administrative expense
Restructuring Cost and Reserve [Line Items]
Pre-tax Restructuring Costs	$ 0.3	$ 0.0