Restructuring Costs - Summary of Costs (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Total expected costs	$ 34.0
Costs incurred	5.8	$ 19.2
Remaining costs at 3/31/2016	9.0
2016 Restructuring Actions
Restructuring Cost and Reserve [Line Items]
Total expected costs	11.3
Costs incurred	5.4	0.0
Remaining costs at 3/31/2016	5.9
2016 Restructuring Actions | Electrical
Restructuring Cost and Reserve [Line Items]
Total expected costs	10.6
Costs incurred	5.1	0.0
Remaining costs at 3/31/2016	5.5
2016 Restructuring Actions | Power
Restructuring Cost and Reserve [Line Items]
Total expected costs	0.7
Costs incurred	0.3	0.0
Remaining costs at 3/31/2016	0.4
2015 and Prior Restructuring Actions
Restructuring Cost and Reserve [Line Items]
Total expected costs	22.7
Costs incurred	0.4	19.2
Remaining costs at 3/31/2016	3.1
2015 and Prior Restructuring Actions | Electrical
Restructuring Cost and Reserve [Line Items]
Total expected costs	20.8
Costs incurred	0.4	17.3
Remaining costs at 3/31/2016	3.1
2015 and Prior Restructuring Actions | Power
Restructuring Cost and Reserve [Line Items]
Total expected costs	1.9
Costs incurred	0.0	$ 1.9
Remaining costs at 3/31/2016	$ 0.0