Restructuring Costs - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Pre-tax Restructuring Costs		$ 12.0	$ 20.3	$ 35.0
Accrued liability settlement term		19 years
Withdrawal from Multiemployer Defined Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Pre-tax Restructuring Costs	$ 12.5
2016 Restructuring Actions | Withdrawal from Multiemployer Defined Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Pre-tax Restructuring Costs	$ 12.5
Electrical
Defined Benefit Plan Disclosure [Line Items]
Pre-tax Restructuring Costs		$ 8.3	$ 16.9	33.9
Electrical | 2016 Restructuring Actions | Withdrawal from Multiemployer Defined Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Pre-tax Restructuring Costs				$ 12.5