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Callaway Energy Center (Narrative) (Details) - Ameren Missouri $ in Millions | 12 Months Ended
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Dec. 31, 2023 USD ($)
Nuclear Waste Matters [Line Items] |
Frequency of Decommissioning Cost Study | 3 years
Minimum | Nuclear Decommissioning Trust Fund |
Nuclear Waste Matters [Line Items] |
Trust Fund Investments, Target Allocation Percentage | 60.00%
Maximum | Nuclear Decommissioning Trust Fund |
Nuclear Waste Matters [Line Items] |
Trust Fund Investments, Target Allocation Percentage | 70.00%
Nuclear Plant |
Nuclear Waste Matters [Line Items] |
Annual decommissioning costs included in costs of service | $ 7

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