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Pension Plans and Other Postretirement Benefits - Expected Future Benefit Payments (Details) $ in Millions | Sep. 30, 2020 USD ($)
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Pension Plans |
Expected benefit payments [Abstract] |
2021 | $ 65.6
2022 | 64.1
2023 | 60.8
2024 | 58.6
2025 | 54.4
2026- 2030 | 246.0
Pension Plans | Spire Missouri |
Expected benefit payments [Abstract] |
2021 | 49.1
2022 | 45.6
2023 | 43.3
2024 | 41.9
2025 | 37.7
2026- 2030 | 168.7
Pension Plans | Spire Alabama |
Expected benefit payments [Abstract] |
2021 | 13.5
2022 | 15.4
2023 | 14.3
2024 | 13.5
2025 | 13.3
2026- 2030 | 59.0
Other Postretirement Plans |
Expected benefit payments [Abstract] |
2021 | 14.7
2022 | 15.4
2023 | 16.1
2024 | 16.5
2025 | 16.6
2026- 2030 | 78.2
Other Postretirement Plans | Spire Missouri |
Expected benefit payments [Abstract] |
2021 | 11.7
2022 | 12.3
2023 | 12.9
2024 | 13.2
2025 | 13.3
2026- 2030 | 61.7
Other Postretirement Plans | Spire Alabama |
Expected benefit payments [Abstract] |
2021 | 2.7
2022 | 2.8
2023 | 2.9
2024 | 3.0
2025 | 3.0
2026- 2030 | $ 14.2

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