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v3.23.2

Related Party Transactions (Effects of Related-party Transactions on the Statement of Income) (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | $ 1,760 | $ 1,726 | $ 3,822 | $ 3,605
Purchased Power | 328 | 318 | 823 | 495
Other operations and maintenance | 450 | 491 | 898 | 952
(Interest Charges)/Other Income, Net | 134 | 126 | 261 | 230
Union Electric Company |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | 941 | 919 | 1,864 | 1,737
Purchased Power | 137 | 161 | 345 | 211
Other operations and maintenance | 237 | 260 | 476 | 492
(Interest Charges)/Other Income, Net | 52 | 60 | 103 | 99
Union Electric Company | Ameren Missouri Power Supply Agreements with Ameren Illinois | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | 1 | 1 | 1 | 5
Union Electric Company | Ameren Missouri and Ameren Illinois Rent and Facility Services | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | 8 | 6 | 18 | 12
Other operations and maintenance | 1 | 1 | 1 | 1
Union Electric Company | Ameren Missouri and Ameren Illinois Miscellaneous Support Services | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | 1 | 1 | 1 | 1
Union Electric Company | Total Related Party Operating Revenues | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | 8 | 7 | 18 | 17
Union Electric Company | Ameren Missouri and Ameren Illinois Transmission Services from ATXI | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Purchased Power | 1 | 1 | 1 | 1
Union Electric Company | Purchased Power | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Purchased Power | 1 | 1 | 1 | 1
Union Electric Company | Ameren Services Support Services Agreement | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Other operations and maintenance | 35 | 33 | 70 | 71
Union Electric Company | Total Related Party Other Operations and Maintenance | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Other operations and maintenance | 35 | 33 | 70 | 71
Union Electric Company | Money pool borrowings (advances) | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
(Interest Charges)/Other Income, Net | 1 | 1 | 1 | 1
Ameren Illinois Company |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | 779 | 769 | 1,880 | 1,793
Purchased Power | 192 | 158 | 479 | 289
Other operations and maintenance | 201 | 225 | 403 | 448
(Interest Charges)/Other Income, Net | 50 | 41 | 97 | 83
Ameren Illinois Company | Ameren Missouri and Ameren Illinois Rent and Facility Services | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | 1 | 1 | 1 | 1
Other operations and maintenance | 1 | 1 | 2 | 1
Ameren Illinois Company | Ameren Missouri and Ameren Illinois Miscellaneous Support Services | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | 1 | 1 | 1 | 1
Ameren Illinois Company | Total Related Party Operating Revenues | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Operating Revenues | 1 | 1 | 1 | 1
Ameren Illinois Company | Ameren Illinois Power Supply Agreements with Ameren Missouri | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Purchased Power | 1 | 1 | 1 | 5
Ameren Illinois Company | Ameren Missouri and Ameren Illinois Transmission Services from ATXI | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Purchased Power | 1 | 1 | 1 | 1
Ameren Illinois Company | Purchased Power | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Purchased Power | 1 | 1 | 1 | 5
Ameren Illinois Company | Ameren Services Support Services Agreement | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Other operations and maintenance | 33 | 32 | 68 | 67
Ameren Illinois Company | Total Related Party Other Operations and Maintenance | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Other operations and maintenance | 33 | 32 | 70 | 68
Ameren Illinois Company | Money pool borrowings (advances) | Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
(Interest Charges)/Other Income, Net | $ 1 | $ 1 | $ 1 | $ 1

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