| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| Operating Revenues: | |||||||||||
| Electric | $ | 1,364 | $ | 1,590 | |||||||
| Natural gas | 452 | 472 | |||||||||
| Total operating revenues | 1,816 | 2,062 | |||||||||
| Operating Expenses: | |||||||||||
| Fuel and purchased power | 328 | 608 | |||||||||
| Natural gas purchased for resale | 151 | 208 | |||||||||
| Other operations and maintenance | 470 | 448 | |||||||||
| Depreciation and amortization | 361 | 320 | |||||||||
| Taxes other than income taxes | 135 | 127 | |||||||||
| Total operating expenses | 1,445 | 1,711 | |||||||||
| Operating Income | 371 | 351 | |||||||||
| Other Income, Net | 89 | 78 | |||||||||
| Interest Charges | 154 | 127 | |||||||||
| Income Before Income Taxes | 306 | 302 | |||||||||
| Income Taxes | 44 | 37 | |||||||||
| Net Income | 262 | 265 | |||||||||
| Less: Net Income Attributable to Noncontrolling Interests | 1 | 1 | |||||||||
| Net Income Attributable to Ameren Common Shareholders | $ | 261 | $ | 264 | |||||||
| Earnings per Common Share – Basic | $ | 0.98 | $ | 1.01 | |||||||
| Earnings per Common Share – Diluted | $ | 0.98 | $ | 1.00 | |||||||
| Weighted-average Common Shares Outstanding – Basic | 266.4 | 262.2 | |||||||||
| Weighted-average Common Shares Outstanding – Diluted | 266.8 | 263.1 | |||||||||
| March 31, 2024 | December 31, 2023 | ||||||||||
| ASSETS | |||||||||||
| Current Assets: | |||||||||||
| Cash and cash equivalents | $ | 85 | $ | 25 | |||||||
| Accounts receivable - trade (less allowance for doubtful accounts) | 507 | 494 | |||||||||
| Unbilled revenue | 272 | 319 | |||||||||
| Miscellaneous accounts receivable | 82 | 106 | |||||||||
| Inventories | 679 | 733 | |||||||||
| Current regulatory assets | 356 | 365 | |||||||||
| Other current assets | 103 | 139 | |||||||||
| Total current assets | 2,084 | 2,181 | |||||||||
| Property, Plant, and Equipment, Net | 34,114 | 33,776 | |||||||||
| Investments and Other Assets: | |||||||||||
| Nuclear decommissioning trust fund | 1,232 | 1,150 | |||||||||
| Goodwill | 411 | 411 | |||||||||
| Regulatory assets | 1,904 | 1,810 | |||||||||
| Pension and other postretirement benefits | 597 | 581 | |||||||||
| Other assets | 964 | 921 | |||||||||
| Total investments and other assets | 5,108 | 4,873 | |||||||||
| TOTAL ASSETS | $ | 41,306 | $ | 40,830 | |||||||
| LIABILITIES AND EQUITY | |||||||||||
| Current Liabilities: | |||||||||||
| Current maturities of long-term debt | $ | 1,149 | $ | 849 | |||||||
| Short-term debt | 868 | 536 | |||||||||
| Accounts and wages payable | 647 | 1,136 | |||||||||
| Customer deposits | 190 | 176 | |||||||||
| Other current liabilities | 651 | 648 | |||||||||
| Total current liabilities | 3,505 | 3,345 | |||||||||
| Long-term Debt, Net | 15,167 | 15,121 | |||||||||
| Deferred Credits and Other Liabilities: | |||||||||||
| Accumulated deferred income taxes and tax credits, net | 4,251 | 4,176 | |||||||||
| Regulatory liabilities | 5,593 | 5,512 | |||||||||
| Asset retirement obligations | 779 | 772 | |||||||||
| Other deferred credits and liabilities | 439 | 426 | |||||||||
| Total deferred credits and other liabilities | 11,062 | 10,886 | |||||||||
| Shareholders’ Equity: | |||||||||||
| Common stock | 3 | 3 | |||||||||
| Other paid-in capital, principally premium on common stock | 7,228 | 7,216 | |||||||||
| Retained earnings | 4,219 | 4,136 | |||||||||
| Accumulated other comprehensive loss | (7) | (6) | |||||||||
| Total shareholders’ equity | 11,443 | 11,349 | |||||||||
| Noncontrolling Interests | 129 | 129 | |||||||||
| Total equity | 11,572 | 11,478 | |||||||||
| TOTAL LIABILITIES AND EQUITY | $ | 41,306 | $ | 40,830 | |||||||
| Three Months Ended March 31, | |||||||||||
| 2024 | 2023 | ||||||||||
| Cash Flows From Operating Activities: | |||||||||||
| Net income | $ | 262 | $ | 265 | |||||||
| Adjustments to reconcile net income to net cash provided by operating activities: | |||||||||||
| Depreciation and amortization | 379 | 350 | |||||||||
| Amortization of nuclear fuel | 18 | 19 | |||||||||
| Amortization of debt issuance costs and premium/discounts | 5 | 3 | |||||||||
| Deferred income taxes and investment tax credits, net | 44 | 35 | |||||||||
| Allowance for equity funds used during construction | (9) | (9) | |||||||||
| Stock-based compensation costs | 8 | 8 | |||||||||
| Other | 16 | (6) | |||||||||
| Changes in assets and liabilities | (231) | (169) | |||||||||
| Net cash provided by operating activities | 492 | 496 | |||||||||
| Cash Flows From Investing Activities: | |||||||||||
| Capital expenditures | (890) | (931) | |||||||||
| Nuclear fuel expenditures | (12) | (20) | |||||||||
| Purchases of securities – nuclear decommissioning trust fund | (70) | (29) | |||||||||
| Sales and maturities of securities – nuclear decommissioning trust fund | 66 | 17 | |||||||||
| Other | — | (1) | |||||||||
| Net cash used in investing activities | (906) | (964) | |||||||||
| Cash Flows From Financing Activities: | |||||||||||
| Dividends on common stock | (178) | (165) | |||||||||
| Dividends paid to noncontrolling interest holders | (1) | (1) | |||||||||
| Short-term debt, net | 332 | 179 | |||||||||
| Issuances of long-term debt | 347 | 499 | |||||||||
| Issuances of common stock | 10 | 5 | |||||||||
| Employee payroll taxes related to stock-based compensation | (8) | (20) | |||||||||
| Debt issuance costs | (5) | (5) | |||||||||
| Other | — | (3) | |||||||||
| Net cash provided by financing activities | 497 | 489 | |||||||||
| Net change in cash, cash equivalents, and restricted cash | 83 | 21 | |||||||||
Cash, cash equivalents, and restricted cash at beginning of year(a) | 272 | 216 | |||||||||
Cash, cash equivalents, and restricted cash at end of period(b) | $ | 355 | $ | 237 | |||||||