Commitments and Contingencies, Environmental (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
Environmental Contingency
Environmental accrual	$ 17.1
Expected period related to remediation expenditures for environmental contingencies period	30 years
Potential increase in environmental costs	$ 11.6
Time period within which Companys recorded estimate of its obligation may change	12 months
Minimum [Member]
Environmental Contingency
Period for final feasibility study	9 months

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Total costs accrued as of the balance sheet date for environmental loss contingencies.

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The difference between the maximum amount of estimated loss and the amount recorded as of the balance sheet date.

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