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COMMITMENTS AND CONTINGENCIES - Contingencies (Details) |  | 3 Months Ended | 69 Months Ended |
--- | --- | --- | --- | ---
Dec. 17, 2013 fatality | Dec. 31, 2017 site plaintiff | Dec. 31, 2017 lawsuit site plaintiff | Sep. 30, 2013 site
Spire Missouri |  |  |  |
Loss Contingencies [Line Items] |  |  |  |
Number of former manufactured gas plant (MGP) sites in Missouri |  | 3 | 3 |
Number of former manufactured gas plant (MGP) sites enrolled in BVCP |  | 2 | 2 |
Spire Alabama |  |  |  |
Loss Contingencies [Line Items] |  |  |  |
Number of former manufactured gas plant (MGP) |  | 9 | 9 |
Number of incident fatalities | fatality | 1 |  |  |
Number of former manufactured gas distribution |  | 5 | 5 |
Spire Gulf |  |  |  |
Loss Contingencies [Line Items] |  |  |  |
Number of lawsuits filed | lawsuit |  |  | 14 |
Number of plaintiffs | plaintiff |  |  | 1,600 |
Previous Ownership | Spire Missouri |  |  |  |
Loss Contingencies [Line Items] |  |  |  |
Number of former manufactured gas plant (MGP) |  |  |  | 19
Previous Ownership | Missouri Gas Energy (MGE) |  |  |  |
Loss Contingencies [Line Items] |  |  |  |
Number of former manufactured gas plant (MGP) |  | 7 | 7 |
Current Ownership | Spire Alabama |  |  |  |
Loss Contingencies [Line Items] |  |  |  |
Number of former manufactured gas plant (MGP) |  | 4 | 4 |
Number of former manufactured gas distribution |  | 1 | 1 |
Pending Litigation | Spire Gulf |  |  |  |
Loss Contingencies [Line Items] |  |  |  |
Number of plaintiffs | plaintiff |  | 31 |  |

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- Definition The total number of new claims filed pertaining to a loss contingency during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349 + Details
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