Commitments and Contingencies (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) LegalMatter claims	Sep. 30, 2016 USD ($)	Dec. 31, 2017 USD ($) claims	Dec. 31, 2015 USD ($)
Loss Contingencies [Line Items]
Number of pending claims (legal matter) | claims	674		687
Number of claims dismissed | claims	74
Number of claims settled (claim) | claims	4
Claims settlements amount	$ 2.5
Asbestos-related claims	$ 75.9		$ 76.2
Recorded third-party environmental recoveries receivable			$ 69.2
Primary coverage period	8 years
Excess coverage period	2 years
Indemnity and defense costs	$ 0.3
Connecticut Voluntary Corrective Action Program (VCAP)
Loss Contingencies [Line Items]
Estimated total cleanup costs, accrual				$ 3.2
Connecticut Voluntary Corrective Action Program
Loss Contingencies [Line Items]
Estimated total cleanup costs, accrual	1.7
Loss contingency accrual, period decrease		$ (0.9)
Environmental remediation expense	0.6
Superfund Sites Proceedings
Loss Contingencies [Line Items]
Estimated total cleanup costs, accrual	$ 0.4
Number of pending claims (legal matter) | LegalMatter	1
Estimated total cleanup costs, cost sharing percentage	2.00%
PCB Contamination Proceedings
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	$ 0.2
Minimum | Superfund Sites Proceedings
Loss Contingencies [Line Items]
Loss contingency, maximum possible loss	18.8
Maximum | Superfund Sites Proceedings
Loss Contingencies [Line Items]
Loss contingency, maximum possible loss	$ 29.6