Contingent Liabilities and Commitments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 20, 2018	Jul. 29, 2016
Environmental assessment and remediation [Member]
Site Contingency [Line Items]
Accrued environmental assessment and remediation costs, total	$ 3.2	$ 3.5
Accrued environmental assessment and remediation costs, current	1.5	1.5
Accrued environmental assessment and remediation costs, noncurrent	1.7	$ 2.0
Environmental assessment and remediation [Member] | Minimum [Member]
Site Contingency [Line Items]
Environmental assessment and remediation costs, best estimate	$ 5.0
Expected duration of environmental assessment and remediation spending	4 years
Environmental assessment and remediation [Member] | Maximum [Member]
Site Contingency [Line Items]
Environmental assessment and remediation costs, best estimate	$ 7.0
Expected duration of environmental assessment and remediation spending	6 years
Potentially responsible party at various Superfund and state waste disposal sites [Member] | Maximum [Member]
Site Contingency [Line Items]
Environmental assessment and remediation costs, best estimate	$ 0.5
Accrued Liabilities
Site Contingency [Line Items]
Notice of Penalty			$ 1.4	$ 1.6