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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Off System Sales (Details) $ in Millions | 12 Months Ended
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Sep. 30, 2017 USD ($)
Spire Missouri East | First $2.0 of pre-tax income |
Off System Sales [Line Items] |
Pre-tax Income | $ 2.0
Customer Share | 85.00%
Company Share | 15.00%
Spire Missouri East | Next $2.0 of pre-tax income |
Off System Sales [Line Items] |
Pre-tax Income | $ 2.0
Customer Share | 80.00%
Company Share | 20.00%
Spire Missouri East | Next $2.0 of pre-tax income |
Off System Sales [Line Items] |
Pre-tax Income | $ 2.0
Customer Share | 75.00%
Company Share | 25.00%
Spire Missouri East | Amounts of pre-tax income exceeding $6.0 |
Off System Sales [Line Items] |
Pre-tax Income | $ 6.0
Customer Share | 70.00%
Company Share | 30.00%
Spire Missouri West | First $1.2 of pre-tax income |
Off System Sales [Line Items] |
Pre-tax Income | $ 1.2
Customer Share | 85.00%
Company Share | 15.00%
Spire Missouri West | Next $1.2 of pre-tax income |
Off System Sales [Line Items] |
Pre-tax Income | $ 1.2
Customer Share | 80.00%
Company Share | 20.00%
Spire Missouri West | Next $1.2 of pre-tax income |
Off System Sales [Line Items] |
Pre-tax Income | $ 1.2
Customer Share | 75.00%
Company Share | 25.00%
Spire Missouri West | Amounts of pre-tax income exceeding $3.6 |
Off System Sales [Line Items] |
Pre-tax Income | $ 3.6
Customer Share | 70.00%
Company Share | 30.00%

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- Definition Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)(1)(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
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- Details
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- Details
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