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Note 13 - Pension Plans and Other Postretirement Benefits - Expected Pension Benefit Payments for Succeeding Fiscal Years (Details) $ in Millions | Sep. 30, 2023 USD ($)
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Pension Plan [Member] |
2024 | $ 52.4
2025 | 45.3
2026 | 41.8
2027 | 41.8
2028 | 43.3
2029-2032 | 202.8
Pension Plan [Member] | Spire Missouri [Member] |
2024 | 41.0
2025 | 34.1
2026 | 30.4
2027 | 29.4
2028 | 30.5
2029-2032 | 139.1
Pension Plan [Member] | Spire Alabama Inc [Member] |
2024 | 8.0
2025 | 7.7
2026 | 7.8
2027 | 8.7
2028 | 8.9
2029-2032 | 44.1
Other Postretirement Benefits Plan [Member] |
2024 | 14.6
2025 | 14.8
2026 | 14.9
2027 | 14.8
2028 | 14.5
2029-2032 | 68.6
Other Postretirement Benefits Plan [Member] | Spire Missouri [Member] |
2024 | 11.6
2025 | 11.8
2026 | 11.8
2027 | 11.7
2028 | 11.4
Other Postretirement Benefits Plan [Member] | Spire Alabama Inc [Member] |
2024 | 2.9
2025 | 2.9
2026 | 2.9
2027 | 2.9
2028 | $ 2.9

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- Definition Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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- Definition Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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- Definition Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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- Definition Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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- Definition Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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- Definition Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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