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v3.24.1.u1

Rate And Regulatory Matters (Narrative-Federal) (Details) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended
--- | --- | ---
May 31, 2020 | Mar. 31, 2024 | Mar. 31, 2023
Rate And Regulatory Matters [Line Items] |  |  |
ROE Change |  | 0.50% |
Revenues |  | $ 1,816 | $ 2,062
Ameren Illinois Company |  |  |
Rate And Regulatory Matters [Line Items] |  |  |
Revenues |  | 1,000 | $ 1,101
Midwest Independent Transmission System Operator, Inc |  |  |
Rate And Regulatory Matters [Line Items] |  |  |
Revenues |  | 21 |
Midwest Independent Transmission System Operator, Inc | Ameren Illinois Company |  |  |
Rate And Regulatory Matters [Line Items] |  |  |
Revenues |  | $ 15 |
Midwest Independent Transmission System Operator, Inc | Final Rate Order |  |  |
Rate And Regulatory Matters [Line Items] |  |  |
Approved return on equity percentage | 10.02% |  |

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