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v3.23.1

Segment Information (Schedule Of Segment Reporting Information By Segment) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Segment Reporting Information [Line Items] |  |
Revenues | $ 2,062 | $ 1,879
Net income (loss) attributable to common shareholders | 264 | 252
Capital expenditures | 931 | 774
Union Electric Company |  |
Segment Reporting Information [Line Items] |  |
Revenues | 923 | 818
Net income (loss) attributable to common shareholders | 28 | 50
Ameren Illinois Company |  |
Segment Reporting Information [Line Items] |  |
Revenues | 1,101 | 1,024
Net income (loss) attributable to common shareholders | 198 | 169
Capital expenditures | 407 | 342
Operating Segments | Union Electric Company |  |
Segment Reporting Information [Line Items] |  |
Revenues | 913 | 808
Net income (loss) attributable to common shareholders | 28 | 50
Capital expenditures | 481 | 414
Operating Segments | Ameren Illinois Electric Distribution |  |
Segment Reporting Information [Line Items] |  |
Revenues | 624 | 464
Net income (loss) attributable to common shareholders | 61 | 49
Capital expenditures | 170 | 138
Operating Segments | Ameren Illinois Natural Gas |  |
Segment Reporting Information [Line Items] |  |
Revenues | 391 | 481
Net income (loss) attributable to common shareholders | 87 | 80
Capital expenditures | 51 | 49
Operating Segments | Ameren Transmission |  |
Segment Reporting Information [Line Items] |  |
Revenues | 134 | 126
Net income (loss) attributable to common shareholders | 71 | 58
Capital expenditures | 213 | 172
Operating Segments | Ameren Illinois Company | Ameren Illinois Electric Distribution |  |
Segment Reporting Information [Line Items] |  |
Revenues | 624 | 465
Net income (loss) attributable to common shareholders | 61 | 49
Capital expenditures | 170 | 138
Operating Segments | Ameren Illinois Company | Ameren Illinois Natural Gas |  |
Segment Reporting Information [Line Items] |  |
Revenues | 391 | 481
Net income (loss) attributable to common shareholders | 87 | 80
Capital expenditures | 51 | 49
Operating Segments | Ameren Illinois Company | Ameren Illinois Transmission |  |
Segment Reporting Information [Line Items] |  |
Revenues | 86 | 78
Net income (loss) attributable to common shareholders | 50 | 40
Capital expenditures | 186 | 155
Other |  |
Segment Reporting Information [Line Items] |  |
Net income (loss) attributable to common shareholders | 17 | 15
Capital expenditures | 3 | 2
Intersegment Eliminations |  |
Segment Reporting Information [Line Items] |  |
Intersegment revenues | (39) | (31)
Capital expenditures | 13 | (1)
Intersegment Eliminations | Union Electric Company |  |
Segment Reporting Information [Line Items] |  |
Intersegment revenues | (10) | (10)
Intersegment Eliminations | Ameren Illinois Electric Distribution |  |
Segment Reporting Information [Line Items] |  |
Intersegment revenues | 0 | (1)
Intersegment Eliminations | Ameren Illinois Natural Gas |  |
Segment Reporting Information [Line Items] |  |
Intersegment revenues | 0 | 0
Intersegment Eliminations | Ameren Transmission |  |
Segment Reporting Information [Line Items] |  |
Intersegment revenues | (29) | (20)
Intersegment Eliminations | Ameren Illinois Company |  |
Segment Reporting Information [Line Items] |  |
Intersegment revenues | (28) | (20)
Intersegment Eliminations | Ameren Illinois Company | Ameren Illinois Electric Distribution |  |
Segment Reporting Information [Line Items] |  |
Intersegment revenues | 0 | 0
Intersegment Eliminations | Ameren Illinois Company | Ameren Illinois Natural Gas |  |
Segment Reporting Information [Line Items] |  |
Intersegment revenues | 0 | 0
Intersegment Eliminations | Ameren Illinois Company | Ameren Illinois Transmission |  |
Segment Reporting Information [Line Items] |  |
Intersegment revenues | $ (28) | $ (20)

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