| Three Months Ended September 30, | Nine Months Ended September 30, | ||||||||||||||||||||||
| 2022 | 2021 | 2022 | 2021 | ||||||||||||||||||||
| Operating Revenues: | |||||||||||||||||||||||
| Electric | $ | 2,140 | $ | 1,668 | $ | 4,971 | $ | 4,108 | |||||||||||||||
| Natural gas | 166 | 143 | 940 | 741 | |||||||||||||||||||
| Total operating revenues | 2,306 | 1,811 | 5,911 | 4,849 | |||||||||||||||||||
| Operating Expenses: | |||||||||||||||||||||||
| Fuel | 117 | 184 | 376 | 422 | |||||||||||||||||||
| Purchased power | 563 | 159 | 1,058 | 479 | |||||||||||||||||||
| Natural gas purchased for resale | 58 | 45 | 431 | 275 | |||||||||||||||||||
| Other operations and maintenance | 475 | 457 | 1,427 | 1,289 | |||||||||||||||||||
| Depreciation and amortization | 350 | 290 | 965 | 856 | |||||||||||||||||||
| Taxes other than income taxes | 144 | 142 | 415 | 392 | |||||||||||||||||||
| Total operating expenses | 1,707 | 1,277 | 4,672 | 3,713 | |||||||||||||||||||
| Operating Income | 599 | 534 | 1,239 | 1,136 | |||||||||||||||||||
| Other Income, Net | 58 | 56 | 180 | 151 | |||||||||||||||||||
| Interest Charges | 126 | 94 | 356 | 290 | |||||||||||||||||||
| Income Before Income Taxes | 531 | 496 | 1,063 | 997 | |||||||||||||||||||
| Income Taxes | 78 | 70 | 148 | 128 | |||||||||||||||||||
| Net Income | 453 | 426 | 915 | 869 | |||||||||||||||||||
| Less: Net Income Attributable to Noncontrolling Interests | 1 | 1 | 4 | 4 | |||||||||||||||||||
| Net Income Attributable to Ameren Common Shareholders | $ | 452 | $ | 425 | $ | 911 | $ | 865 | |||||||||||||||
| Earnings per Common Share – Basic | $ | 1.75 | $ | 1.66 | $ | 3.53 | $ | 3.38 | |||||||||||||||
| Earnings per Common Share – Diluted | $ | 1.74 | $ | 1.65 | $ | 3.51 | $ | 3.36 | |||||||||||||||
| Weighted-average Common Shares Outstanding – Basic | 258.4 | 257.3 | 258.2 | 255.9 | |||||||||||||||||||
| Weighted-average Common Shares Outstanding – Diluted | 259.5 | 258.6 | 259.3 | 257.2 | |||||||||||||||||||
| September 30, 2022 | December 31, 2021 | ||||||||||
| ASSETS | |||||||||||
| Current Assets: | |||||||||||
| Cash and cash equivalents | $ | 7 | $ | 8 | |||||||
| Accounts receivable - trade (less allowance for doubtful accounts) | 665 | 434 | |||||||||
| Unbilled revenue | 366 | 301 | |||||||||
| Miscellaneous accounts receivable | 62 | 85 | |||||||||
| Inventories | 695 | 592 | |||||||||
| Current regulatory assets | 346 | 319 | |||||||||
| Current collateral assets | 145 | 66 | |||||||||
| Other current assets | 232 | 163 | |||||||||
| Total current assets | 2,518 | 1,968 | |||||||||
| Property, Plant, and Equipment, Net | 30,608 | 29,261 | |||||||||
| Investments and Other Assets: | |||||||||||
| Nuclear decommissioning trust fund | 910 | 1,159 | |||||||||
| Goodwill | 411 | 411 | |||||||||
| Regulatory assets | 1,405 | 1,289 | |||||||||
| Pension and other postretirement benefits | 813 | 756 | |||||||||
| Other assets | 992 | 891 | |||||||||
| Total investments and other assets | 4,531 | 4,506 | |||||||||
| TOTAL ASSETS | $ | 37,657 | $ | 35,735 | |||||||
| LIABILITIES AND EQUITY | |||||||||||
| Current Liabilities: | |||||||||||
| Current maturities of long-term debt | $ | 155 | $ | 505 | |||||||
| Short-term debt | 1,221 | 545 | |||||||||
| Accounts and wages payable | 820 | 1,095 | |||||||||
| Taxes accrued | 216 | 74 | |||||||||
| Current regulatory liabilities | 179 | 113 | |||||||||
| Other current liabilities | 584 | 494 | |||||||||
| Total current liabilities | 3,175 | 2,826 | |||||||||
| Long-term Debt, Net | 13,577 | 12,562 | |||||||||
| Deferred Credits and Other Liabilities: | |||||||||||
| Accumulated deferred income taxes and tax credits, net | 3,785 | 3,499 | |||||||||
| Regulatory liabilities | 5,658 | 5,848 | |||||||||
| Asset retirement obligations | 771 | 757 | |||||||||
| Other deferred credits and liabilities | 361 | 414 | |||||||||
| Total deferred credits and other liabilities | 10,575 | 10,518 | |||||||||
| Shareholders’ Equity: | |||||||||||
| Common stock | 3 | 3 | |||||||||
| Other paid-in capital, principally premium on common stock | 6,548 | 6,502 | |||||||||
| Retained earnings | 3,636 | 3,182 | |||||||||
| Accumulated other comprehensive income | 14 | 13 | |||||||||
| Total shareholders’ equity | 10,201 | 9,700 | |||||||||
| Noncontrolling Interests | 129 | 129 | |||||||||
| Total equity | 10,330 | 9,829 | |||||||||
| TOTAL LIABILITIES AND EQUITY | $ | 37,657 | $ | 35,735 | |||||||
| Nine Months Ended September 30, | |||||||||||
| 2022 | 2021 | ||||||||||
| Cash Flows From Operating Activities: | |||||||||||
| Net income | $ | 915 | $ | 869 | |||||||
| Adjustments to reconcile net income to net cash provided by operating activities: | |||||||||||
| Depreciation and amortization | 1,016 | 903 | |||||||||
| Amortization of nuclear fuel | 46 | 37 | |||||||||
| Amortization of debt issuance costs and premium/discounts | 17 | 17 | |||||||||
| Deferred income taxes and investment tax credits, net | 137 | 139 | |||||||||
| Allowance for equity funds used during construction | (31) | (30) | |||||||||
| Stock-based compensation costs | 18 | 17 | |||||||||
| Other | 63 | 11 | |||||||||
| Changes in assets and liabilities | (582) | (771) | |||||||||
| Net cash provided by operating activities | 1,599 | 1,192 | |||||||||
| Cash Flows From Investing Activities: | |||||||||||
| Capital expenditures | (2,437) | (2,613) | |||||||||
| Nuclear fuel expenditures | (22) | (19) | |||||||||
| Purchases of securities – nuclear decommissioning trust fund | (176) | (411) | |||||||||
| Sales and maturities of securities – nuclear decommissioning trust fund | 163 | 404 | |||||||||
| Other | 14 | (7) | |||||||||
| Net cash used in investing activities | (2,458) | (2,646) | |||||||||
| Cash Flows From Financing Activities: | |||||||||||
| Dividends on common stock | (457) | (423) | |||||||||
| Dividends paid to noncontrolling interest holders | (4) | (4) | |||||||||
| Short-term debt, net | 675 | 63 | |||||||||
| Maturities of long-term debt | (450) | — | |||||||||
| Issuances of long-term debt | 1,118 | 1,423 | |||||||||
| Issuances of common stock | 29 | 297 | |||||||||
| Redemptions of Ameren Illinois preferred stock | — | (13) | |||||||||
| Employee payroll taxes related to stock-based compensation | (16) | (17) | |||||||||
| Debt issuance costs | (11) | (15) | |||||||||
| Other | — | (13) | |||||||||
| Net cash provided by financing activities | 884 | 1,298 | |||||||||
| Net change in cash, cash equivalents, and restricted cash | 25 | (156) | |||||||||
| Cash, cash equivalents, and restricted cash at beginning of year | 155 | 301 | |||||||||
| Cash, cash equivalents, and restricted cash at end of period | $ | 180 | $ | 145 | |||||||