| Three Months Ended June 30, | Six Months Ended June 30, | ||||||||||||||||||||||
| 2022 | 2021 | 2022 | 2021 | ||||||||||||||||||||
| Operating Revenues: | |||||||||||||||||||||||
| Electric | $ | 1,513 | $ | 1,284 | $ | 2,831 | $ | 2,440 | |||||||||||||||
| Natural gas | 213 | 188 | 774 | 598 | |||||||||||||||||||
| Total operating revenues | 1,726 | 1,472 | 3,605 | 3,038 | |||||||||||||||||||
| Operating Expenses: | |||||||||||||||||||||||
| Fuel | 83 | 173 | 259 | 238 | |||||||||||||||||||
| Purchased power | 318 | 129 | 495 | 320 | |||||||||||||||||||
| Natural gas purchased for resale | 80 | 65 | 373 | 230 | |||||||||||||||||||
| Other operations and maintenance | 491 | 412 | 952 | 832 | |||||||||||||||||||
| Depreciation and amortization | 316 | 285 | 615 | 566 | |||||||||||||||||||
| Taxes other than income taxes | 129 | 122 | 271 | 250 | |||||||||||||||||||
| Total operating expenses | 1,417 | 1,186 | 2,965 | 2,436 | |||||||||||||||||||
| Operating Income | 309 | 286 | 640 | 602 | |||||||||||||||||||
| Other Income, Net | 62 | 49 | 122 | 95 | |||||||||||||||||||
| Interest Charges | 126 | 96 | 230 | 196 | |||||||||||||||||||
| Income Before Income Taxes | 245 | 239 | 532 | 501 | |||||||||||||||||||
| Income Taxes | 36 | 31 | 70 | 58 | |||||||||||||||||||
| Net Income | 209 | 208 | 462 | 443 | |||||||||||||||||||
| Less: Net Income Attributable to Noncontrolling Interests | 2 | 1 | 3 | 3 | |||||||||||||||||||
| Net Income Attributable to Ameren Common Shareholders | $ | 207 | $ | 207 | $ | 459 | $ | 440 | |||||||||||||||
| Earnings per Common Share – Basic | $ | 0.80 | $ | 0.81 | $ | 1.78 | $ | 1.72 | |||||||||||||||
| Earnings per Common Share – Diluted | $ | 0.80 | $ | 0.80 | $ | 1.77 | $ | 1.71 | |||||||||||||||
| Weighted-average Common Shares Outstanding – Basic | 258.2 | 256.1 | 258.0 | 255.2 | |||||||||||||||||||
| Weighted-average Common Shares Outstanding – Diluted | 259.4 | 257.2 | 259.2 | 256.5 | |||||||||||||||||||
| June 30, 2022 | December 31, 2021 | ||||||||||
| ASSETS | |||||||||||
| Current Assets: | |||||||||||
| Cash and cash equivalents | $ | 7 | $ | 8 | |||||||
| Accounts receivable - trade (less allowance for doubtful accounts) | 519 | 434 | |||||||||
| Unbilled revenue | 400 | 301 | |||||||||
| Miscellaneous accounts receivable | 81 | 85 | |||||||||
| Inventories | 600 | 592 | |||||||||
| Mark-to-market derivative assets | 157 | 66 | |||||||||
| Current regulatory assets | 333 | 319 | |||||||||
| Current collateral assets | 222 | 66 | |||||||||
| Other current assets | 77 | 97 | |||||||||
| Total current assets | 2,396 | 1,968 | |||||||||
| Property, Plant, and Equipment, Net | 30,086 | 29,261 | |||||||||
| Investments and Other Assets: | |||||||||||
| Nuclear decommissioning trust fund | 957 | 1,159 | |||||||||
| Goodwill | 411 | 411 | |||||||||
| Regulatory assets | 1,487 | 1,289 | |||||||||
| Pension and other postretirement benefits | 808 | 756 | |||||||||
| Other assets | 963 | 891 | |||||||||
| Total investments and other assets | 4,626 | 4,506 | |||||||||
| TOTAL ASSETS | $ | 37,108 | $ | 35,735 | |||||||
| LIABILITIES AND EQUITY | |||||||||||
| Current Liabilities: | |||||||||||
| Current maturities of long-term debt | $ | 605 | $ | 505 | |||||||
| Short-term debt | 1,021 | 545 | |||||||||
| Accounts and wages payable | 897 | 1,095 | |||||||||
| Current regulatory liabilities | 241 | 113 | |||||||||
| Other current liabilities | 824 | 568 | |||||||||
| Total current liabilities | 3,588 | 2,826 | |||||||||
| Long-term Debt, Net | 12,985 | 12,562 | |||||||||
| Deferred Credits and Other Liabilities: | |||||||||||
| Accumulated deferred income taxes and tax credits, net | 3,614 | 3,499 | |||||||||
| Regulatory liabilities | 5,727 | 5,848 | |||||||||
| Asset retirement obligations | 774 | 757 | |||||||||
| Other deferred credits and liabilities | 411 | 414 | |||||||||
| Total deferred credits and other liabilities | 10,526 | 10,518 | |||||||||
| Shareholders’ Equity: | |||||||||||
| Common stock | 3 | 3 | |||||||||
| Other paid-in capital, principally premium on common stock | 6,527 | 6,502 | |||||||||
| Retained earnings | 3,336 | 3,182 | |||||||||
| Accumulated other comprehensive income | 14 | 13 | |||||||||
| Total shareholders’ equity | 9,880 | 9,700 | |||||||||
| Noncontrolling Interests | 129 | 129 | |||||||||
| Total equity | 10,009 | 9,829 | |||||||||
| TOTAL LIABILITIES AND EQUITY | $ | 37,108 | $ | 35,735 | |||||||
| Six Months Ended June 30, | |||||||||||
| 2022 | 2021 | ||||||||||
| Cash Flows From Operating Activities: | |||||||||||
| Net income | $ | 462 | $ | 443 | |||||||
| Adjustments to reconcile net income to net cash provided by operating activities: | |||||||||||
| Depreciation and amortization | 665 | 596 | |||||||||
| Amortization of nuclear fuel | 28 | 20 | |||||||||
| Amortization of debt issuance costs and premium/discounts | 12 | 11 | |||||||||
| Deferred income taxes and investment tax credits, net | 66 | 59 | |||||||||
| Allowance for equity funds used during construction | (19) | (16) | |||||||||
| Stock-based compensation costs | 12 | 11 | |||||||||
| Other | 33 | 2 | |||||||||
| Changes in assets and liabilities | (387) | (690) | |||||||||
| Net cash provided by operating activities | 872 | 436 | |||||||||
| Cash Flows From Investing Activities: | |||||||||||
| Capital expenditures | (1,538) | (1,763) | |||||||||
| Nuclear fuel expenditures | (22) | (4) | |||||||||
| Purchases of securities – nuclear decommissioning trust fund | (122) | (203) | |||||||||
| Sales and maturities of securities – nuclear decommissioning trust fund | 114 | 208 | |||||||||
| Other | 16 | 2 | |||||||||
| Net cash used in investing activities | (1,552) | (1,760) | |||||||||
| Cash Flows From Financing Activities: | |||||||||||
| Dividends on common stock | (305) | (282) | |||||||||
| Dividends paid to noncontrolling interest holders | (3) | (3) | |||||||||
| Short-term debt, net | 475 | (59) | |||||||||
| Issuances of long-term debt | 524 | 1,423 | |||||||||
| Issuances of common stock | 17 | 258 | |||||||||
| Redemptions of Ameren Illinois preferred stock | — | (13) | |||||||||
| Employee payroll taxes related to stock-based compensation | (16) | (17) | |||||||||
| Debt issuance costs | (6) | (13) | |||||||||
| Other | — | (4) | |||||||||
| Net cash provided by financing activities | 686 | 1,290 | |||||||||
| Net change in cash, cash equivalents, and restricted cash | 6 | (34) | |||||||||
| Cash, cash equivalents, and restricted cash at beginning of year | 155 | 301 | |||||||||
| Cash, cash equivalents, and restricted cash at end of period | $ | 161 | $ | 267 | |||||||