Consolidated Statement of Stockholders' Equity - USD ($) $ in Millions |
Total |
Common Stock |
Other Paid-in Capital: |
Retained Earnings: |
Derivative Financial Instruments |
Deferred Retirement Benefit Costs |
Accumulated Other Comprehensive Income (Loss): |
Total Shareholders’ Equity |
Noncontrolling Interests: |
Union Electric Company |
Union Electric Company
Common Stock
|
Union Electric Company
Other Paid-in Capital:
|
Union Electric Company
Preferred Stock
|
Union Electric Company
Retained Earnings:
|
Ameren Illinois Company |
Ameren Illinois Company
Common Stock
|
Ameren Illinois Company
Other Paid-in Capital:
|
Ameren Illinois Company
Preferred Stock
|
Ameren Illinois Company
Retained Earnings:
|
| Beginning of period at Dec. 31, 2024 |
|
|
$ 7,513
|
$ 4,604
|
$ 3
|
$ (9)
|
|
|
$ 129
|
|
|
$ 3,201
|
|
$ 4,206
|
|
|
|
|
$ 4,266
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued under the DRPlus and 401(k) plan |
|
|
25
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Stock-based compensation activity |
|
|
3
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Capital contributions from parent |
|
|
|
|
|
|
|
|
|
$ 0
|
|
0
|
|
|
|
|
|
|
|
| Net income |
$ 567
|
|
|
|
|
|
|
|
|
194
|
|
|
|
|
$ 374
|
|
|
|
|
| Net Income Available to Common Shareholder |
|
|
|
564
|
|
|
|
|
|
|
|
|
|
|
373
|
|
|
|
|
| Dividends on common stock |
|
|
|
(384)
|
|
|
|
|
|
|
|
|
|
(50)
|
|
|
|
|
(75)
|
| Dividends on preferred stock |
|
|
|
|
|
|
|
|
|
|
|
|
|
(2)
|
|
|
|
|
(1)
|
| Change in derivative financial instruments |
|
|
|
|
(6)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Change in deferred retirement benefit costs |
(2)
|
|
|
|
|
(2)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Net income attributable to noncontrolling interest holders |
$ (3)
|
|
|
|
|
|
|
|
3
|
|
|
|
|
|
|
|
|
|
|
| Dividends paid to noncontrolling interest holders |
|
|
|
|
|
|
|
|
(3)
|
|
|
|
|
|
|
|
|
|
|
| Common stock shares outstanding at beginning of period at Dec. 31, 2024 |
269,900,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued under the DRPlus and 401(k) plan |
200,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued for stock-based compensation |
300,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Common stock shares outstanding at end of period at Jun. 30, 2025 |
270,400,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| End of period at Jun. 30, 2025 |
$ 12,443
|
$ 3
|
7,541
|
4,784
|
(3)
|
(11)
|
$ (14)
|
|
129
|
|
$ 511
|
3,201
|
$ 80
|
4,348
|
|
$ 0
|
$ 3,056
|
$ 49
|
4,564
|
| Shareholders' equity, end of year at Jun. 30, 2025 |
|
|
|
|
|
|
|
$ 12,314
|
|
8,140
|
|
|
|
|
7,669
|
|
|
|
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Dividends per common share |
$ 1.42
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Beginning of period at Mar. 31, 2025 |
|
|
7,524
|
4,702
|
(1)
|
(9)
|
|
|
129
|
|
|
3,201
|
|
4,198
|
|
|
|
|
4,427
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued under the DRPlus and 401(k) plan |
|
|
10
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Stock-based compensation activity |
|
|
7
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Capital contributions from parent |
|
|
|
|
|
|
|
|
|
|
|
0
|
|
|
|
|
|
|
|
| Net income |
$ 277
|
|
|
|
|
|
|
|
|
151
|
|
|
|
|
138
|
|
|
|
|
| Net Income Available to Common Shareholder |
|
|
|
275
|
|
|
|
|
|
|
|
|
|
|
137
|
|
|
|
|
| Dividends on common stock |
|
|
|
(193)
|
|
|
|
|
|
|
|
|
|
0
|
|
|
|
|
0
|
| Dividends on preferred stock |
|
|
|
|
|
|
|
|
|
|
|
|
|
(1)
|
|
|
|
|
(1)
|
| Change in derivative financial instruments |
|
|
|
|
(2)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Change in deferred retirement benefit costs |
(2)
|
|
|
|
|
(2)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Net income attributable to noncontrolling interest holders |
$ (2)
|
|
|
|
|
|
|
|
2
|
|
|
|
|
|
|
|
|
|
|
| Dividends paid to noncontrolling interest holders |
|
|
|
|
|
|
|
|
(2)
|
|
|
|
|
|
|
|
|
|
|
| Common stock shares outstanding at beginning of period at Mar. 31, 2025 |
270,300,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued under the DRPlus and 401(k) plan |
100,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued for stock-based compensation |
0
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Common stock shares outstanding at end of period at Jun. 30, 2025 |
270,400,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| End of period at Jun. 30, 2025 |
$ 12,443
|
3
|
7,541
|
4,784
|
(3)
|
(11)
|
(14)
|
|
129
|
|
511
|
3,201
|
80
|
4,348
|
|
0
|
3,056
|
49
|
4,564
|
| Shareholders' equity, end of year at Jun. 30, 2025 |
|
|
|
|
|
|
|
12,314
|
|
$ 8,140
|
|
|
|
|
$ 7,669
|
|
|
|
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Dividends per common share |
$ 0.71
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Beginning of period at Dec. 31, 2025 |
$ 13,530
|
|
8,106
|
5,292
|
6
|
(6)
|
|
|
129
|
|
|
3,229
|
|
4,757
|
|
|
|
|
4,736
|
| Common stock shares outstanding at beginning of period at Dec. 31, 2025 |
276,400,000
|
|
|
|
|
|
|
|
|
102,100,000
|
|
|
|
|
25,500,000
|
|
|
|
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued for stock-based compensation |
200,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Common stock shares outstanding at end of period at Mar. 31, 2026 |
276,700,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| End of period at Mar. 31, 2026 |
|
|
8,114
|
5,441
|
4
|
(6)
|
|
|
129
|
|
|
3,579
|
|
4,833
|
|
|
|
|
4,862
|
| Beginning of period at Dec. 31, 2025 |
$ 13,530
|
|
8,106
|
5,292
|
6
|
(6)
|
|
|
129
|
|
|
3,229
|
|
4,757
|
|
|
|
|
4,736
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued under the DRPlus and 401(k) plan |
|
|
22
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Stock-based compensation activity |
|
|
4
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Capital contributions from parent |
|
|
|
|
|
|
|
|
|
$ 425
|
|
425
|
|
|
|
|
|
|
|
| Net income |
674
|
|
|
|
|
|
|
|
|
$ 235
|
|
|
|
|
$ 404
|
|
|
|
|
| Net Income Available to Common Shareholder |
|
|
|
671
|
|
|
|
|
|
|
|
|
|
|
$ 403
|
|
|
|
|
| Dividends on common stock |
|
|
|
(414)
|
|
|
|
|
|
|
|
|
|
0
|
|
|
|
|
(265)
|
| Dividends on preferred stock |
|
|
|
|
|
|
|
|
|
|
|
|
|
(2)
|
|
|
|
|
(1)
|
| Change in derivative financial instruments |
|
|
|
|
4
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Change in deferred retirement benefit costs |
(1)
|
|
|
|
|
(1)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Net income attributable to noncontrolling interest holders |
$ (3)
|
|
|
|
|
|
|
|
3
|
|
|
|
|
|
|
|
|
|
|
| Dividends paid to noncontrolling interest holders |
|
|
|
|
|
|
|
|
(3)
|
|
|
|
|
|
|
|
|
|
|
| Common stock shares outstanding at beginning of period at Dec. 31, 2025 |
276,400,000
|
|
|
|
|
|
|
|
|
102,100,000
|
|
|
|
|
25,500,000
|
|
|
|
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued under the DRPlus and 401(k) plan |
200,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued for stock-based compensation |
200,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Common stock shares outstanding at end of period at Jun. 30, 2026 |
276,800,000
|
|
|
|
|
|
|
|
|
102,100,000
|
|
|
|
|
25,500,000
|
|
|
|
|
| End of period at Jun. 30, 2026 |
$ 13,816
|
3
|
8,132
|
5,549
|
10
|
(7)
|
3
|
|
129
|
|
511
|
3,654
|
80
|
4,990
|
|
0
|
3,058
|
49
|
4,874
|
| Shareholders' equity, end of year at Jun. 30, 2026 |
$ 13,687
|
|
|
|
|
|
|
13,687
|
|
$ 9,235
|
|
|
|
|
$ 7,981
|
|
|
|
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Dividends per common share |
$ 1.50
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Beginning of period at Mar. 31, 2026 |
|
|
8,114
|
5,441
|
4
|
(6)
|
|
|
129
|
|
|
3,579
|
|
4,833
|
|
|
|
|
4,862
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued under the DRPlus and 401(k) plan |
|
|
10
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Stock-based compensation activity |
|
|
8
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Capital contributions from parent |
|
|
|
|
|
|
|
|
|
75
|
|
75
|
|
|
|
|
|
|
|
| Net income |
$ 316
|
|
|
|
|
|
|
|
|
$ 158
|
|
|
|
|
148
|
|
|
|
|
| Net Income Available to Common Shareholder |
|
|
|
314
|
|
|
|
|
|
|
|
|
|
|
$ 147
|
|
|
|
|
| Dividends on common stock |
|
|
|
(206)
|
|
|
|
|
|
|
|
|
|
0
|
|
|
|
|
(135)
|
| Dividends on preferred stock |
|
|
|
|
|
|
|
|
|
|
|
|
|
(1)
|
|
|
|
|
(1)
|
| Change in derivative financial instruments |
|
|
|
|
6
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Change in deferred retirement benefit costs |
(1)
|
|
|
|
|
(1)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Net income attributable to noncontrolling interest holders |
$ (2)
|
|
|
|
|
|
|
|
2
|
|
|
|
|
|
|
|
|
|
|
| Dividends paid to noncontrolling interest holders |
|
|
|
|
|
|
|
|
(2)
|
|
|
|
|
|
|
|
|
|
|
| Common stock shares outstanding at beginning of period at Mar. 31, 2026 |
276,700,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued under the DRPlus and 401(k) plan |
100,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Shares issued for stock-based compensation |
0
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Common stock shares outstanding at end of period at Jun. 30, 2026 |
276,800,000
|
|
|
|
|
|
|
|
|
102,100,000
|
|
|
|
|
25,500,000
|
|
|
|
|
| End of period at Jun. 30, 2026 |
$ 13,816
|
$ 3
|
$ 8,132
|
$ 5,549
|
$ 10
|
$ (7)
|
$ 3
|
|
$ 129
|
|
$ 511
|
$ 3,654
|
$ 80
|
$ 4,990
|
|
$ 0
|
$ 3,058
|
$ 49
|
$ 4,874
|
| Shareholders' equity, end of year at Jun. 30, 2026 |
$ 13,687
|
|
|
|
|
|
|
$ 13,687
|
|
$ 9,235
|
|
|
|
|
$ 7,981
|
|
|
|
|
| Increase (Decrease) in Stockholders' Equity [Roll Forward] |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Dividends per common share |
$ 0.75
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|