Restructuring Costs and Other - Summary of Costs (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Total expected costs	$ 36.0
Costs incurred	10.4	$ 12.0
Remaining costs at 6/30/2019	13.6
2019 Restructuring Actions
Restructuring Cost and Reserve [Line Items]
Total expected costs	17.5
Costs incurred	9.2	0.0
Remaining costs at 6/30/2019	8.3
2019 Restructuring Actions | Electrical
Restructuring Cost and Reserve [Line Items]
Total expected costs	15.0
Costs incurred	7.0	0.0
Remaining costs at 6/30/2019	8.0
2019 Restructuring Actions | Power
Restructuring Cost and Reserve [Line Items]
Total expected costs	2.5
Costs incurred	2.2	0.0
Remaining costs at 6/30/2019	0.3
2018 and Prior Restructuring Actions
Restructuring Cost and Reserve [Line Items]
Total expected costs	18.5
Costs incurred	1.2	12.0
Remaining costs at 6/30/2019	5.3
2018 and Prior Restructuring Actions | Electrical
Restructuring Cost and Reserve [Line Items]
Total expected costs	13.6
Costs incurred	0.4	8.3
Remaining costs at 6/30/2019	4.9
2018 and Prior Restructuring Actions | Power
Restructuring Cost and Reserve [Line Items]
Total expected costs	4.9
Costs incurred	0.8	$ 3.7
Remaining costs at 6/30/2019	$ 0.4