Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Environmental remediation liabilities - discounted	$ 39.1	$ 40.4
Accrual for environmental loss contingencies - weighted-average discount rate	3.70%	3.70%
Environmental remediation liabilities - undiscounted	$ 72.7	$ 74.5
Minimum
Loss Contingencies [Line Items]
Potential revision on future environmental remediation costs before tax	10.0
Maximum
Loss Contingencies [Line Items]
Potential revision on future environmental remediation costs before tax	35.0
Other noncurrent liabilities
Loss Contingencies [Line Items]
Tax Indemnification Liability	27.8	$ 45.3
Accrued expenses
Loss Contingencies [Line Items]
Tax Indemnification Liability	$ 19.2