Commitments and Contingencies, Textuals (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015
Environmental Contingency
Contractual Obligation	$ 14.7us-gaap_ContractualObligation
Environmental accrual	19.4
Expected period related to remediation expenditures for environmental contingencies period	30 years
Potential increase in environmental costs	$ 24.7
Minimum
Environmental Contingency
Period for final feasibility study	18 months
Maximum
Environmental Contingency
Period for final feasibility study	24 months

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- Definition

Period For Final Feasibility Study

+ References

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 30

-Section 50

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

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-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 25

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346

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- Definition

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

+ References

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 05

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6395354&loc=d3e12631-108344

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