Restructuring Costs and Other - Summary of Costs (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Total expected costs	$ 31.2
Costs incurred	0.6	$ 24.1
Remaining costs at 3/31/2021	6.5
2021 Restructuring Actions
Restructuring Cost and Reserve [Line Items]
Total expected costs	0.0
Costs incurred	0.0	0.0
Remaining costs at 3/31/2021	0.0
2020 and Prior Restructuring Actions
Restructuring Cost and Reserve [Line Items]
Total expected costs	31.2
Costs incurred	0.6	24.1
Remaining costs at 3/31/2021	6.5
2020 and Prior Restructuring Actions | Electrical Solutions
Restructuring Cost and Reserve [Line Items]
Total expected costs	21.3
Costs incurred	0.3	16.0
Remaining costs at 3/31/2021	5.0
2020 and Prior Restructuring Actions | Utility Solutions
Restructuring Cost and Reserve [Line Items]
Total expected costs	9.9
Costs incurred	0.3	$ 8.1
Remaining costs at 3/31/2021	$ 1.5