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Commitments and Contingencies - Lead Refinery Site (Details) - Lead Refinery Site [Member] - Non operating Properties [Member] $ in Millions | 1 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2014 USD ($) property | Jul. 01, 2017 USD ($) | Sep. 27, 2014 potentially_responsible_party | Jul. 17, 2009 potentially_responsible_party
Site Contingency [Line Items] |  |  |  |
Estimated number of years until mitigation resolution |  | 20 years |  |
Number of parties involved in settlement negotiations | potentially_responsible_party |  |  | 2 | 2
EPA's estimated cost of site remediation | $ 26.0 |  |  |
Number of surrounding properties | property | 300 |  |  |
Minimum [Member] |  |  |  |
Site Contingency [Line Items] |  |  |  |
Mitigation estimates |  | $ 2.1 |  |
Maximum [Member] |  |  |  |
Site Contingency [Line Items] |  |  |  |
Mitigation estimates |  | $ 4.7 |  |

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- Definition Estimate of reasonably possible loss exposure in excess of amount accrued for remediation, site restoration, postclosure, monitoring commitments, or other exit costs associated with the sale, disposal or abandonment of a particular property resulting from unanticipated contamination of the assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14394-108349 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 5.Y.Q4) -URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751 + Details
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