Restructuring Costs and Other - Summary of Costs (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Total expected costs	$ 32.8
Costs incurred	3.5	$ 24.1
Remaining costs at 9/30/2021	5.2
2021 Restructuring Actions
Restructuring Cost and Reserve [Line Items]
Total expected costs	2.5
Costs incurred	0.7	0.0
Remaining costs at 9/30/2021	1.8
2021 Restructuring Actions | Electrical Solutions
Restructuring Cost and Reserve [Line Items]
Total expected costs	2.5
Costs incurred	0.7	0.0
Remaining costs at 9/30/2021	1.8
2021 Restructuring Actions | Utility Solutions
Restructuring Cost and Reserve [Line Items]
Total expected costs	0.0
Costs incurred	0.0	0.0
Remaining costs at 9/30/2021	0.0
2020 and Prior Restructuring Actions
Restructuring Cost and Reserve [Line Items]
Total expected costs	30.3
Costs incurred	2.8	24.1
Remaining costs at 9/30/2021	3.4
2020 and Prior Restructuring Actions | Electrical Solutions
Restructuring Cost and Reserve [Line Items]
Total expected costs	20.0
Costs incurred	2.0	16.0
Remaining costs at 9/30/2021	2.0
2020 and Prior Restructuring Actions | Utility Solutions
Restructuring Cost and Reserve [Line Items]
Total expected costs	10.3
Costs incurred	0.8	$ 8.1
Remaining costs at 9/30/2021	$ 1.4