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PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Pre-tax Amortization from AOCI (Details) $ in Millions | 12 Months Ended
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Sep. 30, 2017 USD ($)
Pension Plans |
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract] |
Amortization of net actuarial loss | $ 12.6
Amortization of prior service (credit) cost | (0.9)
Subtotal | 11.7
Regulatory adjustment | (11.4)
Total | 0.3
Postretirement Plans |
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract] |
Amortization of net actuarial loss | 0.9
Amortization of prior service (credit) cost | (0.1)
Subtotal | 0.8
Regulatory adjustment | (0.8)
Total | 0.0
Spire Missouri | Pension Plans |
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract] |
Amortization of net actuarial loss | 10.5
Amortization of prior service (credit) cost | 0.9
Subtotal | 11.4
Regulatory adjustment | (11.1)
Total | 0.3
Spire Missouri | Postretirement Plans |
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract] |
Amortization of net actuarial loss | 0.9
Amortization of prior service (credit) cost | 0.3
Subtotal | 1.2
Regulatory adjustment | (1.2)
Total | 0.0
Spire Alabama | Pension Plans |
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract] |
Amortization of net actuarial loss | 2.1
Amortization of prior service (credit) cost | (1.8)
Subtotal | 0.3
Regulatory adjustment | (0.3)
Total | 0.0
Spire Alabama | Postretirement Plans |
Pre-tax amounts are expected to be amortized from accumulated other comprehensive income [Abstract] |
Amortization of net actuarial loss | 0.0
Amortization of prior service (credit) cost | (0.4)
Subtotal | (0.4)
Regulatory adjustment | 0.4
Total | $ 0.0

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- Definition The aggregate amount in accumulated other comprehensive income, net of regulatory adjustments, expected to be recognized as a component of net periodic benefit cost over the fiscal year that follows the most recent annual statement of financial position presented, including the net gain (loss), net prior service cost or credit, and net transition asset or obligation. + References No definition available. + Details
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- Definition The difference between the period's net periodic cost for defined benefit plans calculated in accordance with GAAP and the amount of recovery allowed in rates by the regulatory agency. These differences are deferred as regulatory assets or regulatory liabilities. + References No definition available. + Details
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- Definition Amount of cost (credit) included in accumulated other comprehensive (income) loss expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (s) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount included in accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan expected to be recognized in net periodic benefit (cost) credit for fiscal year following most recent annual statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (s) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount included in accumulated other comprehensive (income) loss for prior service cost (credit) expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (s) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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