Contingencies - Narrative (Details) - USD ($) $ in Millions		3 Months Ended
	Jun. 09, 2015	Sep. 30, 2021	Mar. 31, 2021
Loss Contingencies [Line Items]
Loss Contingency, Receivable		$ 6.4
Former Gain Contingency, Recognized in Current Period		4.7
Property, Plant and Equipment, Additions		2.6
Accrued Liabilities [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual		11.7
Highway Products Litigation | False Claims Act, USA
Loss Contingencies [Line Items]
Loss Contingency, Judgment Entered, Value	$ 682.4
Highway Products Litigation | State, County, and Municipal Actions [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual		0.0
Environmental and Workplace Matters [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual		1.4
Loss from Catastrophes
Loss Contingencies [Line Items]
Loss Contingency, Receivable			$ 1.2
Loss Contingency, Receivable, Proceeds		14.6
Collectibility of Receivables
Loss Contingencies [Line Items]
Loss Contingency, Receivable, Proceeds		1.2
Damage from Fire, Explosion or Other Hazard
Loss Contingencies [Line Items]
Loss Contingency, Receivable, Proceeds		8.1
Minimum
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss		11.2
Maximum
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss		$ 18.4