Document and Entity Information
Document and Entity Information - shares | 3 Months Ended | |
Mar. 31, 2019 | Apr. 30, 2019 | |
Entity Information [Line Items] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Mar. 31, 2019 | |
Document Fiscal Year Focus | 2019 | |
Document Fiscal Period Focus | Q1 | |
Trading Symbol | AEE | |
Entity Current Reporting Status | Yes | |
Entity Registrant Name | AMEREN CORP | |
Entity Central Index Key | 0001002910 | |
Current Fiscal Year End Date | --12-31 | |
Entity Emerging Growth Company | false | |
Entity Small Business | false | |
Entity Filer Category | Large Accelerated Filer | |
Entity Common Stock, Shares Outstanding | 245,597,156 | |
Union Electric Company | ||
Entity Information [Line Items] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Mar. 31, 2019 | |
Document Fiscal Year Focus | 2019 | |
Document Fiscal Period Focus | Q1 | |
Entity Current Reporting Status | Yes | |
Entity Registrant Name | UNION ELECTRIC CO | |
Entity Central Index Key | 0000100826 | |
Current Fiscal Year End Date | --12-31 | |
Entity Emerging Growth Company | false | |
Entity Small Business | false | |
Entity Filer Category | Non-accelerated Filer | |
Entity Common Stock, Shares Outstanding | 102,123,834 | |
Ameren Illinois Company | ||
Entity Information [Line Items] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Mar. 31, 2019 | |
Document Fiscal Year Focus | 2019 | |
Document Fiscal Period Focus | Q1 | |
Entity Current Reporting Status | Yes | |
Entity Registrant Name | AMEREN ILLINOIS CO | |
Entity Central Index Key | 0000018654 | |
Current Fiscal Year End Date | --12-31 | |
Entity Emerging Growth Company | false | |
Entity Small Business | false | |
Entity Filer Category | Non-accelerated Filer | |
Entity Common Stock, Shares Outstanding | 25,452,373 |
Consolidated Statement of Incom
Consolidated Statement of Income (Loss) and Comprehensive Income (Loss) - USD ($) shares in Millions, $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Operating Revenues: | ||
Revenue from Contract with Customer, Including Assessed Tax | $ 1,556 | $ 1,585 |
Operating Expenses: | ||
Fuel | 160 | 188 |
Utilities Operating Expense, Purchased Power | 156 | 163 |
Utilities Operating Expense, Gas and Petroleum Purchased | 161 | 171 |
Other operations and maintenance | 417 | 431 |
Depreciation and amortization | 248 | 234 |
Taxes other than income taxes | 126 | 125 |
Total operating expenses | 1,268 | 1,312 |
Operating Income | 288 | 273 |
Other Income (Expense), Net | 29 | 23 |
Interest Charges | 97 | 101 |
Income Before Income Taxes | 220 | 195 |
Income Taxes | 27 | 42 |
Net income | 193 | 153 |
Less: Net Income Attributable to Noncontrolling Interests | 2 | 2 |
Net Income (Loss) Available to Common Stockholders, Basic | 191 | 151 |
Pension and other postretirement benefit plan activity, net of income taxes (benefit) | 1 | 1 |
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest | 194 | 154 |
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest | 2 | 2 |
Comprehensive Income | $ 192 | $ 152 |
Earnings Per Share, Basic and Diluted [Abstract] | ||
Earnings Per Share, Basic and Diluted | $ 0.78 | $ 0.62 |
Average Common Shares Outstanding - Basic (in shares) | 244.9 | 242.9 |
Weighted Average Number of Shares Outstanding, Diluted | 246.4 | 244.4 |
Electricity | ||
Operating Revenues: | ||
Revenue from Contract with Customer, Including Assessed Tax | $ 1,182 | $ 1,223 |
Natural Gas | ||
Operating Revenues: | ||
Revenue from Contract with Customer, Including Assessed Tax | 374 | 362 |
Union Electric Company | ||
Operating Revenues: | ||
Revenue from Contract with Customer, Including Assessed Tax | 758 | 792 |
Operating Expenses: | ||
Fuel | 160 | 188 |
Utilities Operating Expense, Purchased Power | 51 | 42 |
Utilities Operating Expense, Gas and Petroleum Purchased | 27 | 24 |
Other operations and maintenance | 224 | 232 |
Depreciation and amortization | 140 | 136 |
Taxes other than income taxes | 77 | 80 |
Total operating expenses | 679 | 702 |
Operating Income | 79 | 90 |
Other Income (Expense), Net | 12 | 13 |
Interest Charges | 47 | 51 |
Income Before Income Taxes | 44 | 52 |
Income Taxes | 4 | 13 |
Net income | 40 | 39 |
Preferred Stock Dividends | 1 | 1 |
Net Income (Loss) Attributable to Parent | 39 | 38 |
Union Electric Company | Electricity | ||
Operating Revenues: | ||
Revenue from Contract with Customer, Including Assessed Tax | 704 | 741 |
Union Electric Company | Natural Gas | ||
Operating Revenues: | ||
Revenue from Contract with Customer, Including Assessed Tax | 54 | 51 |
Ameren Illinois Company | ||
Operating Revenues: | ||
Revenue from Contract with Customer, Including Assessed Tax | 762 | 760 |
Operating Expenses: | ||
Utilities Operating Expense, Purchased Power | 105 | 124 |
Utilities Operating Expense, Gas and Petroleum Purchased | 134 | 147 |
Other operations and maintenance | 191 | 199 |
Depreciation and amortization | 101 | 90 |
Taxes other than income taxes | 45 | 41 |
Total operating expenses | 576 | 601 |
Operating Income | 186 | 159 |
Other Income (Expense), Net | 11 | 6 |
Interest Charges | 37 | 37 |
Income Before Income Taxes | 160 | 128 |
Income Taxes | 39 | 32 |
Net income | 121 | 96 |
Preferred Stock Dividends | 1 | 1 |
Net Income (Loss) Attributable to Parent | 120 | 95 |
Ameren Illinois Company | Electricity | ||
Operating Revenues: | ||
Revenue from Contract with Customer, Including Assessed Tax | 442 | 449 |
Ameren Illinois Company | Natural Gas | ||
Operating Revenues: | ||
Revenue from Contract with Customer, Including Assessed Tax | $ 320 | $ 311 |
Consolidated Statement of Inc_2
Consolidated Statement of Income (Loss) and Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Income Statement [Abstract] | ||
Pension and other postretirement benefit plan activity, tax expense (benefit) | $ 0 | $ 0 |
Consolidated Balance Sheet
Consolidated Balance Sheet - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018 |
Current Assets: | ||
Cash and cash equivalents | $ 8 | $ 16 |
Accounts receivable - trade (less allowance for doubtful accounts) | 517 | 463 |
Unbilled revenue | 238 | 295 |
Miscellaneous accounts and notes receivable | 74 | 79 |
Inventories | 402 | 483 |
Current regulatory assets | 113 | 134 |
Other current assets | 70 | 63 |
Total current assets | 1,422 | 1,533 |
Property, Plant, and Equipment, Net | 23,044 | 22,810 |
Investments and Other Assets: | ||
Nuclear decommissioning trust fund | 754 | 684 |
Goodwill | 411 | 411 |
Regulatory Assets, Noncurrent | 1,134 | 1,127 |
Other assets | 744 | 650 |
Total investments and other assets | 3,043 | 2,872 |
TOTAL ASSETS | 27,509 | 27,215 |
Current Liabilities: | ||
Current maturities of long-term debt | 336 | 580 |
Short-term Debt | 799 | 597 |
Accounts and wages payable | 522 | 817 |
Taxes accrued | 81 | 53 |
Interest accrued | 81 | 93 |
Customer deposits | 111 | 116 |
Current regulatory liabilities | 161 | 149 |
Other current liabilities | 301 | 282 |
Total current liabilities | 2,392 | 2,687 |
Long-term Debt, Net | 8,221 | 7,859 |
Deferred Credits and Other Liabilities: | ||
Accumulated deferred income taxes, net | 2,666 | 2,623 |
Accumulated Deferred Investment Tax Credit | 42 | 43 |
Regulatory Liability, Noncurrent | 4,731 | 4,637 |
Asset retirement obligations | 630 | 627 |
Pension and other postretirement benefits | 558 | 558 |
Other deferred credits and liabilities | 422 | 408 |
Total deferred credits and other liabilities | 9,049 | 8,896 |
Commitments and Contingencies | ||
Stockholders' Equity: | ||
Common Stock | 2 | 2 |
Other paid-in capital | 5,625 | 5,627 |
Retained earnings | 2,099 | 2,024 |
Accumulated other comprehensive loss | (21) | (22) |
Stockholder's equity | 7,705 | 7,631 |
Noncontrolling Interest | 142 | 142 |
Total equity | 7,847 | 7,773 |
TOTAL LIABILITIES AND EQUITY | 27,509 | 27,215 |
Union Electric Company | ||
Current Assets: | ||
Cash and cash equivalents | 0 | 0 |
Accounts receivable - trade (less allowance for doubtful accounts) | 189 | 223 |
Accounts receivable - affiliates | 20 | 14 |
Unbilled revenue | 128 | 155 |
Miscellaneous accounts and notes receivable | 40 | 42 |
Inventories | 329 | 358 |
Current regulatory assets | 13 | 14 |
Other current assets | 32 | 26 |
Total current assets | 751 | 832 |
Property, Plant, and Equipment, Net | 12,159 | 12,103 |
Investments and Other Assets: | ||
Nuclear decommissioning trust fund | 754 | 684 |
Regulatory Assets, Noncurrent | 351 | 366 |
Other assets | 356 | 306 |
Total investments and other assets | 1,461 | 1,356 |
TOTAL ASSETS | 14,371 | 14,291 |
Current Liabilities: | ||
Current maturities of long-term debt | 336 | 580 |
Short-term Debt | 55 | 55 |
Accounts and wages payable | 224 | 428 |
Accounts payable - affiliates | 69 | 69 |
Taxes accrued | 62 | 27 |
Interest accrued | 47 | 52 |
Current regulatory liabilities | 64 | 68 |
Other current liabilities | 128 | 123 |
Total current liabilities | 985 | 1,402 |
Long-term Debt, Net | 3,780 | 3,418 |
Deferred Credits and Other Liabilities: | ||
Accumulated deferred income taxes, net | 1,536 | 1,534 |
Accumulated Deferred Investment Tax Credit | 41 | 42 |
Regulatory Liability, Noncurrent | 2,868 | 2,799 |
Asset retirement obligations | 626 | 623 |
Pension and other postretirement benefits | 227 | 228 |
Other deferred credits and liabilities | 40 | 16 |
Total deferred credits and other liabilities | 5,338 | 5,242 |
Commitments and Contingencies | ||
Stockholders' Equity: | ||
Common Stock | 511 | 511 |
Other paid-in capital | 1,903 | 1,903 |
Preferred stock | 80 | 80 |
Retained earnings | 1,774 | 1,735 |
Stockholder's equity | 4,268 | 4,229 |
TOTAL LIABILITIES AND EQUITY | 14,371 | 14,291 |
Ameren Illinois Company | ||
Current Assets: | ||
Cash and cash equivalents | 0 | 0 |
Accounts receivable - trade (less allowance for doubtful accounts) | 315 | 224 |
Accounts receivable - affiliates | 18 | 21 |
Unbilled revenue | 110 | 140 |
Miscellaneous accounts and notes receivable | 34 | 40 |
Inventories | 73 | 125 |
Current regulatory assets | 92 | 110 |
Other current assets | 15 | 16 |
Total current assets | 657 | 676 |
Property, Plant, and Equipment, Net | 9,347 | 9,198 |
Investments and Other Assets: | ||
Goodwill | 411 | 411 |
Regulatory Assets, Noncurrent | 776 | 759 |
Other assets | 303 | 275 |
Total investments and other assets | 1,490 | 1,445 |
TOTAL ASSETS | 11,494 | 11,319 |
Current Liabilities: | ||
Short-term Debt | 126 | 72 |
Accounts and wages payable | 242 | 302 |
Accounts payable - affiliates | 63 | 58 |
Taxes accrued | 19 | 23 |
Interest accrued | 27 | 31 |
Customer deposits | 73 | 76 |
Current environmental remediation | 45 | 42 |
Current regulatory liabilities | 79 | 62 |
Other current liabilities | 129 | 130 |
Total current liabilities | 803 | 796 |
Long-term Debt, Net | 3,296 | 3,296 |
Deferred Credits and Other Liabilities: | ||
Accumulated deferred income taxes, net | 1,151 | 1,119 |
Regulatory Liability, Noncurrent | 1,765 | 1,741 |
Pension and other postretirement benefits | 281 | 280 |
Environmental remediation | 101 | 109 |
Other deferred credits and liabilities | 203 | 204 |
Total deferred credits and other liabilities | 3,501 | 3,453 |
Commitments and Contingencies | ||
Stockholders' Equity: | ||
Common Stock | 0 | 0 |
Other paid-in capital | 2,173 | 2,173 |
Preferred stock | 62 | 62 |
Retained earnings | 1,659 | 1,539 |
Stockholder's equity | 3,894 | 3,774 |
TOTAL LIABILITIES AND EQUITY | $ 11,494 | $ 11,319 |
Consolidated Balance Sheet (Par
Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018 |
Accounts receivable - trade allowance for doubtful accounts | $ 19 | $ 18 |
Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |
Common stock, shares authorized (in shares) | 400,000,000 | 400,000,000 |
Common Stock, Shares, Outstanding | 245,600,000 | 244,500,000 |
Union Electric Company | ||
Accounts receivable - trade allowance for doubtful accounts | $ 7 | $ 7 |
Common stock, par value (in dollars per share) | $ 5 | $ 5 |
Common stock, shares authorized (in shares) | 150,000,000 | 150,000,000 |
Common Stock, Shares, Outstanding | 102,100,000 | 102,100,000 |
Ameren Illinois Company | ||
Accounts receivable - trade allowance for doubtful accounts | $ 12 | $ 11 |
Common stock, no par value (in dollars per share) | $ 0 | $ 0 |
Common stock, shares authorized (in shares) | 45,000,000 | 45,000,000 |
Common Stock, Shares, Outstanding | 25,500,000 | 25,500,000 |
Consolidated Statement of Cash
Consolidated Statement of Cash Flows - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Cash Flows From Operating Activities: | ||
Net income | $ 193 | $ 153 |
Adjustments to reconcile net income to net cash provided by operating activities: | ||
Depreciation and amortization | 245 | 230 |
Amortization of nuclear fuel | 23 | 24 |
Amortization of debt issuance costs and premium/discounts | 5 | 5 |
Deferred income taxes and investment tax credits, net | 32 | 26 |
Allowance for equity funds used during construction | (6) | (5) |
Stock-based compensation costs | 6 | 6 |
Other | (8) | 2 |
Changes in assets and liabilities: | ||
Receivables | 4 | (26) |
Inventories | 81 | 68 |
Accounts and wages payable | (213) | (249) |
Taxes accrued | 28 | 49 |
Regulatory assets and liabilities | 26 | 20 |
Assets, other | (14) | 1 |
Liabilities, other | (11) | (57) |
Pension and other postretirement benefits | (4) | 11 |
Net cash provided by operating activities | 387 | 258 |
Cash Flows From Investing Activities: | ||
Capital expenditures | (544) | (579) |
Nuclear fuel expenditures | (21) | (12) |
Purchases of securities - nuclear decommissioning trust fund | (39) | (38) |
Sales and maturities of securities - nuclear decommissioning trust fund | 36 | 34 |
Other | 1 | (2) |
Net cash used in investing activities | (567) | (597) |
Cash Flows From Financing Activities: | ||
Dividends on common stock | (116) | (111) |
Dividends paid to noncontrolling interest holders | (2) | (2) |
Short-term debt, net | 202 | 475 |
Repayments of Long-term Debt | (329) | 0 |
Proceeds from Issuance of Long-term Debt | 450 | 0 |
Issuance of common stock | 19 | 17 |
Employee payroll taxes related to stock-based compensation | (29) | (19) |
Payment of Financing and Stock Issuance Costs | (4) | 0 |
Net cash provided by financing activities | 191 | 360 |
Net change in cash, cash equivalents, and restricted cash | 11 | 21 |
Cash, cash equivalents, and restricted cash at beginning of year | 107 | 68 |
Cash, cash equivalents, and restricted cash at end of period | 118 | 89 |
Noncash financing activity - Issuance of common stock for stock-based compensation | 54 | 35 |
Union Electric Company | ||
Cash Flows From Operating Activities: | ||
Net income | 40 | 39 |
Adjustments to reconcile net income to net cash provided by operating activities: | ||
Depreciation and amortization | 138 | 132 |
Amortization of nuclear fuel | 23 | 24 |
Amortization of debt issuance costs and premium/discounts | 2 | 2 |
Deferred income taxes and investment tax credits, net | (1) | (1) |
Allowance for equity funds used during construction | (4) | (4) |
Other | 2 | 4 |
Changes in assets and liabilities: | ||
Receivables | 56 | 4 |
Inventories | 29 | 5 |
Accounts and wages payable | (167) | (192) |
Taxes accrued | 44 | 36 |
Regulatory assets and liabilities | 11 | 38 |
Assets, other | (16) | (5) |
Liabilities, other | (4) | (10) |
Pension and other postretirement benefits | (1) | 4 |
Net cash provided by operating activities | 152 | 76 |
Cash Flows From Investing Activities: | ||
Capital expenditures | (240) | (249) |
Nuclear fuel expenditures | (21) | (12) |
Purchases of securities - nuclear decommissioning trust fund | (39) | (38) |
Sales and maturities of securities - nuclear decommissioning trust fund | 36 | 34 |
Net cash used in investing activities | (264) | (265) |
Cash Flows From Financing Activities: | ||
Dividends on common stock | 0 | (50) |
Dividends on preferred stock | (1) | (1) |
Short-term debt, net | 0 | 243 |
Repayments of Long-term Debt | (329) | 0 |
Proceeds from Issuance of Long-term Debt | 450 | 0 |
Payment of Financing and Stock Issuance Costs | (4) | 0 |
Net cash provided by financing activities | 116 | 192 |
Net change in cash, cash equivalents, and restricted cash | 4 | 3 |
Cash, cash equivalents, and restricted cash at beginning of year | 8 | 7 |
Cash, cash equivalents, and restricted cash at end of period | 12 | 10 |
Ameren Illinois Company | ||
Cash Flows From Operating Activities: | ||
Net income | 121 | 96 |
Adjustments to reconcile net income to net cash provided by operating activities: | ||
Depreciation and amortization | 100 | 90 |
Amortization of debt issuance costs and premium/discounts | 3 | 3 |
Deferred income taxes and investment tax credits, net | 24 | 9 |
Allowance for equity funds used during construction | (2) | (1) |
Other | (1) | (2) |
Changes in assets and liabilities: | ||
Receivables | (56) | (34) |
Inventories | 52 | 63 |
Accounts and wages payable | (34) | (52) |
Taxes accrued | 12 | 1 |
Regulatory assets and liabilities | 18 | (16) |
Assets, other | 3 | 2 |
Liabilities, other | (12) | (36) |
Pension and other postretirement benefits | (3) | 6 |
Net cash provided by operating activities | 227 | 130 |
Cash Flows From Investing Activities: | ||
Capital expenditures | (267) | (300) |
Net cash used in investing activities | (267) | (300) |
Cash Flows From Financing Activities: | ||
Dividends on preferred stock | (1) | (1) |
Short-term debt, net | 54 | 162 |
Capital contribution from parent | 0 | 20 |
Net cash provided by financing activities | 53 | 181 |
Net change in cash, cash equivalents, and restricted cash | 13 | 11 |
Cash, cash equivalents, and restricted cash at beginning of year | 80 | 41 |
Cash, cash equivalents, and restricted cash at end of period | $ 93 | $ 52 |
Consolidated Statement of Stock
Consolidated Statement of Stockholders' Equity Consolidated Statement of Stockholders' Equity - USD ($) shares in Millions, $ in Millions | Total | Common Stock | Other Paid-in Capital | Retained Earnings | Deferred Retirement Benefit Costs | Accumulated Other Comprehensive Income (Loss) | Noncontrolling Interest | Total Ameren Corporation Stockholders' Equity | Union Electric Company | Union Electric CompanyCommon Stock | Union Electric CompanyOther Paid-in Capital | Union Electric CompanyPreferred Stock Not Subject To Mandatory Redemption | Union Electric CompanyRetained Earnings | Ameren Illinois Company | Ameren Illinois CompanyCommon Stock | Ameren Illinois CompanyOther Paid-in Capital | Ameren Illinois CompanyPreferred Stock Not Subject To Mandatory Redemption | Ameren Illinois CompanyRetained Earnings |
Beginning of year at Dec. 31, 2017 | $ 5,540 | $ 1,660 | $ (18) | $ 142 | $ 1,632 | $ 2,013 | $ 1,235 | |||||||||||
Stock Issued During Period, Value, New Issues | 17 | |||||||||||||||||
Stock-based compensation activity | (11) | |||||||||||||||||
Capital contribution from parent | $ 20 | 20 | ||||||||||||||||
Net income | $ 153 | $ 39 | 39 | 96 | 96 | |||||||||||||
Net Income (Loss) Available to Common Stockholders, Basic | 151 | 151 | ||||||||||||||||
Common stock dividends | (111) | (50) | ||||||||||||||||
Preferred stock dividends | (1) | (1) | ||||||||||||||||
Stockholders' Equity, Other | 1 | |||||||||||||||||
Change in deferred retirement benefit costs | (1) | 1 | ||||||||||||||||
Net income attributable to noncontrolling interest holder | $ 2 | 2 | ||||||||||||||||
Dividends paid to noncontrolling interest holders | (2) | |||||||||||||||||
Beginning of year (shares) at Dec. 31, 2017 | 242.6 | |||||||||||||||||
Stock Issued During Period, Shares, New Issues | 0.3 | |||||||||||||||||
Stock Issued During Period, Shares, Other | 0.7 | |||||||||||||||||
End of year (shares) at Mar. 31, 2018 | 243.6 | |||||||||||||||||
End of year at Mar. 31, 2018 | $ 7,372 | $ 2 | 5,546 | 1,699 | (17) | $ (17) | 142 | $ 511 | $ 1,858 | $ 80 | 1,620 | $ 0 | 2,033 | $ 62 | 1,330 | |||
Dividends per Common Share (in dollars per share) | $ 0.4575 | |||||||||||||||||
Stockholders' equity, end of year at Mar. 31, 2018 | $ 7,230 | 4,069 | 3,425 | |||||||||||||||
Beginning of year at Dec. 31, 2018 | $ 7,773 | 5,627 | 2,024 | (22) | 142 | 1,735 | 2,173 | 1,539 | ||||||||||
Stock Issued During Period, Value, New Issues | 19 | |||||||||||||||||
Stock-based compensation activity | (21) | |||||||||||||||||
Capital contribution from parent | 0 | 0 | ||||||||||||||||
Net income | 193 | $ 40 | 40 | $ 121 | 121 | |||||||||||||
Net Income (Loss) Available to Common Stockholders, Basic | 191 | 191 | ||||||||||||||||
Common stock dividends | (116) | 0 | ||||||||||||||||
Preferred stock dividends | (1) | (1) | ||||||||||||||||
Stockholders' Equity, Other | 0 | |||||||||||||||||
Change in deferred retirement benefit costs | (1) | 1 | ||||||||||||||||
Net income attributable to noncontrolling interest holder | $ 2 | 2 | ||||||||||||||||
Dividends paid to noncontrolling interest holders | (2) | |||||||||||||||||
Beginning of year (shares) at Dec. 31, 2018 | 244.5 | 102.1 | 25.5 | |||||||||||||||
Stock Issued During Period, Shares, New Issues | 0.3 | |||||||||||||||||
Stock Issued During Period, Shares, Other | 0.8 | |||||||||||||||||
End of year (shares) at Mar. 31, 2019 | 245.6 | 102.1 | 25.5 | |||||||||||||||
End of year at Mar. 31, 2019 | $ 7,847 | $ 2 | $ 5,625 | $ 2,099 | $ (21) | $ (21) | $ 142 | $ 511 | $ 1,903 | $ 80 | $ 1,774 | $ 0 | $ 2,173 | $ 62 | $ 1,659 | |||
Dividends per Common Share (in dollars per share) | $ 0.4750 | |||||||||||||||||
Stockholders' equity, end of year at Mar. 31, 2019 | $ 7,705 | $ 7,705 | $ 4,268 | $ 3,894 |
Summary Of Significant Accounti
Summary Of Significant Accounting Policies | 3 Months Ended |
Mar. 31, 2019 | |
Accounting Policies [Abstract] | |
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES | SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES General Ameren, headquartered in St. Louis, Missouri, is a public utility holding company whose primary assets are its equity interests in its subsidiaries. Ameren’s subsidiaries are separate, independent legal entities with separate businesses, assets, and liabilities. Dividends on Ameren’s common stock and the payment of expenses by Ameren depend on distributions made to it by its subsidiaries. Ameren’s principal subsidiaries are listed below. Ameren has other subsidiaries that conduct other activities, such as providing shared services. • Union Electric Company, doing business as Ameren Missouri, operates a rate-regulated electric generation, transmission, and distribution business and a rate-regulated natural gas distribution business in Missouri. • Ameren Illinois Company, doing business as Ameren Illinois, operates rate-regulated electric transmission, electric distribution, and natural gas distribution businesses in Illinois. • ATXI operates a FERC rate-regulated electric transmission business. ATXI placed the Spoon River project in service in February 2018, and is developing two additional MISO-approved electric transmission projects, the Illinois Rivers and Mark Twain projects. Ameren’s financial statements are prepared on a consolidated basis and therefore include the accounts of its majority-owned subsidiaries. All intercompany transactions have been eliminated. Ameren Missouri and Ameren Illinois have no subsidiaries. All tabular dollar amounts are in millions, unless otherwise indicated. Our accounting policies conform to GAAP. Our financial statements reflect all adjustments (which include normal, recurring adjustments) that are necessary, in our opinion, for a fair statement of our results. The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions. Such estimates and assumptions affect reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the dates of financial statements, and the reported amounts of revenues and expenses during the reported periods. Actual results could differ from those estimates. The results of operations of an interim period may not give a true indication of results that may be expected for a full year. These financial statements should be read in conjunction with the financial statements and accompanying notes included in the Form 10-K. Variable Interest Entities As of March 31, 2019 , Ameren and Ameren Missouri had interests in unconsolidated variable interest entities that were established to construct wind generation facilities and, ultimately, sell those constructed facilities to Ameren Missouri. Neither Ameren nor Ameren Missouri are the primary beneficiary of these variable interest entities because neither has the power to direct matters that most significantly affect the entities' activities, which include designing, financing, and constructing the wind generation facilities. As a result, these variable interest entities have not been consolidated. As of March 31, 2019 , the maximum exposure to loss related to these variable interest entities was approximately $16 million , which represents the portion of interconnection study costs that may be incurred by Ameren and Ameren Missouri. The risk of a loss was assessed to be remote and, accordingly, Ameren and Ameren Missouri have not recognized a liability associated with any portion of the maximum exposure to loss. See Note 2 – Rate and Regulatory Matters for additional information on the agreements to acquire these wind generation facilities. As of March 31, 2019 , and December 31, 2018 , Ameren had unconsolidated variable interests as a limited partner in various equity method investments, totaling $23 million and $22 million , respectively, included in “Other assets” on Ameren’s consolidated balance sheet. Ameren is not the primary beneficiary of these investments because it does not have the power to direct matters that most significantly affect the activities of these variable interest entities. As of March 31, 2019 , the maximum exposure to loss related to these variable interests is limited to the investment in these partnerships of $23 million plus associated outstanding funding commitments of $15 million . Company-owned Life Insurance Ameren and Ameren Illinois have company-owned life insurance, which is recorded at the net cash surrender value. The net cash surrender value is the amount that can be realized under the insurance policies at the balance sheet date. As of March 31, 2019 , the cash surrender value of company-owned life insurance at Ameren and Ameren Illinois was $ 258 million ( December 31, 2018 – $244 million ) and $ 123 million ( December 31, 2018 – $122 million ), respectively, while total borrowings against the policies were $ 113 million ( December 31, 2018 – $113 million ) at both Ameren and Ameren Illinois. Ameren and Ameren Illinois have the right to offset the borrowings against the cash surrender value of the policies and, consequently, present the net asset in “Other assets” on their respective balance sheets. Accounting and Reporting Developments See Note 13 – Supplemental Information for additional information on our adoption of authoritative accounting guidance related to leases. See Note 1 – Summary of Significant Accounting Policies under Part II, Item 8, of the Form 10-K for additional information about recently issued authoritative accounting standards relating to the measurement of credit losses on financial instruments, fair value measurement disclosures, and defined benefit plan disclosures. |
Rate And Regulatory Matters
Rate And Regulatory Matters | 3 Months Ended |
Mar. 31, 2019 | |
Public Utilities, General Disclosures [Abstract] | |
RATE AND REGULATORY MATTERS | RATE AND REGULATORY MATTERS Below is a summary of updates to significant regulatory proceedings and related lawsuits. See also Note 2 – Rate and Regulatory Matters under Part II, Item 8, of the Form 10-K. We are unable to predict the ultimate outcome of these matters, the timing of the final decisions of the various agencies and courts, or the impact on our results of operations, financial position, or liquidity. Missouri Wind Generation Facilities and RESRAM In May 2019, Ameren Missouri entered into a build-transfer agreement with a subsidiary of Enel Green Power North America, Inc. to acquire, after construction, an up-to 300 - megawatt wind generation facility to be located in northwestern Missouri. Ameren Missouri expects to file for a certificate of convenience and necessity with the MoPSC in May 2019. Final RTO interconnection costs are expected to be determined in June 2019, and a related RTO transmission interconnection agreement is expected in the fall of 2019. In 2018, Ameren Missouri entered into two build-transfer agreements to acquire, after construction, an up-to 400 - megawatt wind generation facility and an up-to 157 - megawatt wind generation facility. In October 2018, the MoPSC issued an order approving a unanimous stipulation and agreement regarding a requested certificate of convenience and necessity for the up-to 400-megawatt facility. In March 2019, the MoPSC issued an order approving a nonunanimous stipulation and agreement regarding a requested certificate of convenience and necessity for the up-to 157-megawatt facility. Final MISO interconnection costs for the up-to 400-megawatt facility are expected to be determined in June 2019, and a related transmission interconnection agreement with the MISO is expected in the fall of 2019. Final MISO interconnection costs for the up-to 157-megawatt facility are expected to be determined in the fall of 2019, and a related transmission interconnection agreement with the MISO is expected in early 2020. All three facilities are expected to be completed by the end of 2020, which would support Ameren Missouri’s compliance with the Missouri renewable energy standard. Each acquisition is subject to certain conditions, including the issuance of a certificate of convenience and necessity by the MoPSC for the up-to 300-megawatt facility, obtaining FERC approval for the up-to 157-megawatt facility and the up-to 300-megawatt facility, entering into an RTO transmission interconnection agreement at an acceptable cost for each facility, and other customary contract terms and conditions. The three build-transfer agreements collectively represent approximately $1.4 billion of capital expenditures expected in 2020. In January 2019, the MoOPC filed an appeal with the Missouri Court of Appeals, Western District, challenging the MoPSC’s December 2018 order allowing Ameren Missouri to recover, through the RESRAM, the 15% of depreciation expense and weighted average cost of capital return not recovered under PISA. Ameren Missouri expects a decision by the end of 2019. The RESRAM is designed to mitigate the impacts of regulatory lag for the cost of compliance with renewable energy standards, including recovery of investments in wind and other renewable generation, by providing more timely recovery of costs and a return on investments not already provided for in customer rates or recovered under PISA. RESRAM regulatory assets earn carrying costs at short-term interest rates. MEEIA As a result of MoPSC orders issued in September 2017, October 2018, and January 2019 related to performance incentives for the MEEIA 2013 and MEEIA 2016 programs, Ameren Missouri recognized gains of $20 million and $5 million during the three months ended March 31, 2019 and 2018, respectively. 2018 Natural Gas Delivery Service Regulatory Rate Review In December 2018, Ameren Missouri filed a request with the MoPSC to increase its annual revenues for natural gas delivery service by approximately $4 million , prior to the interim rate reduction discussed below. The natural gas delivery service rate increase request is based on a 10.30% return on equity, a capital structure composed of 51.84% common equity, a rate base of $259 million , and a test year ended June 30, 2018, with certain pro-forma adjustments through the anticipated true-up date of May 31, 2019. In December 2018, the MoPSC issued an order approving a stipulation and agreement for an interim rate reduction of $2 million to reflect cost of service updates including the reduction in the federal corporate income tax rate and the amortization of excess deferred taxes as a result of the TCJA. As a result of the interim rate reduction, Ameren Missouri's requested annual revenues reflect a $6 million increase from interim rates. The interim rate reduction became effective January 2, 2019, and will continue until new rates are approved by the MoPSC in this regulatory rate review. In April 2019, the MoPSC staff recommended a $1 million increase to interim rates, based on a 9.5% return on equity and a 50% ceiling on the common equity ratio. Illinois Electric Distribution Service Rates In April 2019, Ameren Illinois filed its annual electric distribution service formula rate update to establish the revenue requirement to be used for 2020 rates with the ICC. Pending ICC approval, this update filing will result in a $7 million decrease in Ameren Illinois’ electric distribution service rates, beginning in January 2020. This update reflects an increase to the annual formula rate based on 2018 actual costs and expected net plant additions for 2019, and an increase to include the 2018 revenue requirement reconciliation adjustment. It also reflects a decrease for the conclusion of the 2017 revenue requirement reconciliation adjustment, which will be fully collected from customers in 2019, consistent with the ICC’s November 2018 annual update filing order. An ICC decision in this proceeding is expected by December 2019. As of March 31, 2019 , Ameren Illinois had recorded a regulatory asset of $41 million to reflect the difference between Ameren Illinois’ estimate of its 2019 revenue requirement and the revenue requirement reflected in customer rates, including interest. ATXI’s Illinois Rivers Project In August 2017, the Illinois Circuit Court for Edgar County dismissed several of ATXI’s condemnation cases related to one line segment in the Illinois Rivers project. These cases had been filed to obtain easements and rights of way necessary to complete the line segment. The court found that required notice was not given to the relevant landowners during the underlying ICC proceeding. Upon appeal, in October 2018, the Illinois Supreme Court reversed the Illinois Circuit Court for Edgar County’s decision and remanded the case for further proceedings. In December 2018, the Illinois Supreme Court issued an order to stay its October 2018 ruling. In February 2019, the landowners filed an appeal with the United States Supreme Court, which was denied in April 2019. In the second quarter of 2019, ATXI intends to seek to reinstate the condemnation cases that were previously dismissed. ATXI expects to complete the line segment in 2020. The estimated line segment capital expenditure investment is approximately $81 million , of which $38 million was invested as of March 31, 2019 . The other eight line segments of the Illinois Rivers project have already been completed and placed in-service and are not affected by these proceedings. Federal FERC Complaint Cases In November 2013, a customer group filed a complaint case with the FERC seeking a reduction in the allowed base return on common equity for FERC-regulated transmission rate base under the MISO tariff from 12.38% to 9.15% . In September 2016, the FERC issued an order in the November 2013 complaint case, which lowered the allowed base return on common equity to 10.32%, or a 10.82% total allowed return on common equity with the inclusion of a 50 basis point incentive adder for participation in an RTO, effective since September 2016. The 10.82% allowed return on common equity may be replaced prospectively after the FERC issues a final order in the February 2015 complaint case, discussed below. Since the maximum FERC-allowed refund period for the November 2013 complaint case ended in February 2015, another customer complaint case was filed in February 2015. MISO transmission owners subsequently filed a motion to dismiss the February 2015 complaint, as discussed below. The February 2015 complaint case seeks a further reduction in the allowed base return on common equity for FERC-regulated transmission rate base under the MISO tariff. In June 2016, an administrative law judge issued an initial decision in the February 2015 complaint case. If approved by the FERC, it would lower the allowed base return on common equity for the 15-month period of February 2015 to May 2016 to 9.70% , or a 10.20% total allowed return on equity with the inclusion of a 50 basis point incentive adder for participation in an RTO. It would also require customer refunds, with interest, for that 15-month period. A final FERC order would also establish the allowed return on common equity that will apply prospectively from the effective date of such order, replacing the current 10.82% total return on common equity. In April 2017, the United States Court of Appeals for the District of Columbia Circuit vacated and remanded to the FERC an order in an unrelated case in which the FERC established the allowed base return on common equity methodology subsequently used in the two MISO complaint cases described above. In October 2018, the FERC issued an order in an unrelated case that proposed a new methodology for determining the base return on equity and required further briefs from the participants. In November 2018, the FERC issued an order related to the February 2015 complaint case and the September 2016 order, which required participants to file briefs in February 2019 regarding the FERC’s proposed methodology for determining the base return on common equity, including whether and how to apply the proposed methodology to the two MISO complaint cases. In March 2019, the FERC issued separate Notices of Inquiry regarding its allowed base return on common equity policy and its transmission incentives policy, with comments due in June 2019. The Notice of Inquiry addressing the FERC’s return on common equity policy, among other things, broadens the ability to comment on the new methodology beyond electric utilities that are participants in the complaint cases, and the transmission incentives Notice of Inquiry is open for industry comment on the FERC’s transmission incentive policy, including incentive adders to the return on common equity. Ameren is unable to predict the ultimate impact of the proposed methodology on these complaint cases or the Notices of Inquiry at this time. As the FERC is under no deadline to issue a final order, the timing of the final order in the February 2015 complaint case, and any potential impact to the amounts refunded as a result of the September 2016 order, is uncertain. In September 2017, MISO transmission owners, including Ameren Missouri, Ameren Illinois, and ATXI, filed a motion to dismiss the February 2015 complaint case with the FERC. The MISO transmission owners maintain that the February 2015 complaint was predicated on the now superseded 12.38% allowed base return on common equity and is therefore inapplicable given the current 10.32% allowed base return on common equity. The MISO transmission owners further maintain that the current 10.32% allowed base return on common equity has not been proven to be unjust and unreasonable based on information provided, including the base return on common equity methodology ranges set forth in the February 2015 complaint case and in the initial decision issued by an administrative law judge in June 2016. Additionally, the MISO transmission owners maintain that the February 2015 complaint should be dismissed because the approach utilized in the case to assert that a return on common equity was unjust and unreasonable was insufficient. That same approach was rejected by the United States Court of Appeals for the District of Columbia Circuit in an unrelated case, as discussed above. The FERC is under no deadline to issue an order on this motion. As of March 31, 2019 , Ameren and Ameren Illinois had recorded current regulatory liabilities of $44 million and $26 million , respectively, to reflect the expected refunds, including interest, associated with the reduced allowed return on common equity in the initial decision in the February 2015 complaint case. Ameren Missouri does not expect that a reduction in the FERC-allowed base return on common equity would be material to its results of operations, financial position, or liquidity. |
Short-Term Debt And Liquidity
Short-Term Debt And Liquidity | 3 Months Ended |
Mar. 31, 2019 | |
Debt Disclosure [Abstract] | |
SHORT-TERM DEBT AND LIQUIDITY | SHORT-TERM DEBT AND LIQUIDITY The liquidity needs of the Ameren Companies are typically supported through the use of available cash, drawings under committed credit agreements, commercial paper issuances, and, in the case of Ameren Missouri and Ameren Illinois, short-term affiliate borrowings. See Note 4 – Short-term Debt and Liquidity under Part II, Item 8, in the Form 10-K for a description of our indebtedness provisions and other covenants as well as a description of money pool arrangements. The Missouri Credit Agreement and the Illinois Credit Agreement were not utilized for direct borrowings during the three months ended March 31, 2019 , but were used to support commercial paper issuances and to issue letters of credit. Based on commercial paper outstanding and letters of credit issued under the Credit Agreements, the aggregate credit capacity available under the Credit Agreements to Ameren (parent), Ameren Missouri, and Ameren Illinois, collectively, at March 31, 2019 , was $1.3 billion . The Ameren Companies were in compliance with the covenants in their Credit Agreements as of March 31, 2019 . As of March 31, 2019 , the ratios of consolidated indebtedness to consolidated total capitalization, calculated in accordance with the provisions of the Credit Agreements, were 54% , 48% , and 47% for Ameren, Ameren Missouri, and Ameren Illinois, respectively. Commercial Paper The following table presents commercial paper outstanding, net of issuance discounts, as of March 31, 2019 , and December 31, 2018 : March 31, 2019 December 31, 2018 Ameren (parent) $ 618 $ 470 Ameren Missouri 55 55 Ameren Illinois 126 72 Ameren consolidated $ 799 $ 597 The following table summarizes the borrowing activity and relevant interest rates under Ameren (parent)’s, Ameren Missouri’s, and Ameren Illinois’ commercial paper programs for the three months ended March 31, 2019 and 2018: Ameren (parent) Ameren Missouri Ameren Illinois Ameren Consolidated 2019 Average daily commercial paper outstanding at par value $ 480 $ 246 $ 89 $ 815 Weighted-average interest rate 2.87 % 2.84 % 2.76 % 2.85 % Peak commercial paper during period at par value (a) $ 618 $ 549 $ 130 $ 1,113 Peak interest rate 3.10 % 2.97 % 2.90 % 3.10 % 2018 Average daily commercial paper outstanding at par value $ 378 $ 213 $ 137 $ 728 Weighted-average interest rate 1.90 % 1.88 % 1.96 % 1.90 % Peak commercial paper during period at par value (a) $ 454 $ 282 $ 238 $ 960 Peak interest rate 2.35 % 2.40 % 2.55 % 2.55 % (a) The timing of peak outstanding commercial paper issuances varies by company. Therefore, the sum of individual company peak amounts may not equal the Ameren consolidated peak commercial paper issuances for the period. Money Pools Ameren has money pool agreements with and among its subsidiaries to coordinate and provide for certain short-term cash and working capital requirements. The average interest rate for borrowings under the money pool for the three months ended March 31, 2019 and 2018 , was 2.87% and 1.90% , respectively. See Note 8 – Related-party Transactions for the amount of interest income and expense from the money pool arrangements recorded by the Ameren Companies for the three months ended March 31, 2019 and 2018 . |
Long-Term Debt And Equity Finan
Long-Term Debt And Equity Financings | 3 Months Ended |
Mar. 31, 2019 | |
Long-Term Debt And Equity Financings [Abstract] | |
LONG-TERM DEBT AND EQUITY FINANCINGS | LONG-TERM DEBT AND EQUITY FINANCINGS Ameren For the three months ended March 31, 2019 , Ameren issued a total of 0.3 million shares of common stock under its DRPlus and 401(k) plan, and received proceeds of $19 million . In addition, in the first quarter of 2019, Ameren issued 0.8 million shares of common stock valued at $54 million upon the vesting of stock-based compensation. Ameren Missouri In March 2019, Ameren Missouri issued $450 million of 3.50% first mortgage bonds due March 2029, with interest payable semiannually on March 15 and September 15 of each year, beginning September 15, 2019. Ameren Missouri received net proceeds of $447 million , which were used to repay outstanding short-term debt, including short-term debt that Ameren Missouri incurred in connection with the repayment of $329 million of its 6.70% senior secured notes that matured February 1, 2019. Indenture Provisions and Other Covenants See Note 5 – Long-Term Debt and Equity Financings under Part II, Item 8, in the Form 10-K for a description of our indenture provisions and other covenants, as well as restrictions on the payment of dividends. At March 31, 2019 , the Ameren Companies were in compliance with the provisions and covenants contained in their indentures and articles of incorporation, as applicable, and ATXI was in compliance with the provisions and covenants contained in its note purchase agreement. Off-balance-sheet Arrangements At March 31, 2019 , none of the Ameren Companies had any significant off-balance-sheet financing arrangements, other than variable interest entities, letters of credit, and Ameren (parent) guarantee arrangements on behalf of its subsidiaries. See Note 1 – Summary of Significant Accounting Policies for further detail concerning variable interest entities. |
Other Income and Expenses
Other Income and Expenses | 3 Months Ended |
Mar. 31, 2019 | |
Other Nonoperating Income (Expense) [Abstract] | |
OTHER INCOME AND EXPENSES | OTHER INCOME, NET The following table presents the components of “Other Income, Net” in the Ameren Companies’ statements of income for the three months ended March 31, 2019 and 2018 : Three Months 2019 2018 Ameren: Three Months 2019 2018 Allowance for equity funds used during construction $ 6 $ 5 Interest income on industrial development revenue bonds 6 6 Other interest income 2 2 Non-service cost components of net periodic benefit income (a) 22 16 Miscellaneous income 2 1 Donations (6 ) (5 ) Miscellaneous expense (3 ) (2 ) Total Other Income, Net $ 29 $ 23 Ameren Missouri: Allowance for equity funds used during construction $ 4 $ 4 Interest income on industrial development revenue bonds 6 6 Non-service cost components of net periodic benefit income (a) 4 5 Miscellaneous income 1 1 Donations (2 ) (1 ) Miscellaneous expense (1 ) (2 ) Total Other Income, Net $ 12 $ 13 Ameren Illinois: Allowance for equity funds used during construction $ 2 $ 1 Interest income 2 2 Non-service cost components of net periodic benefit income 12 7 Miscellaneous income 1 — Donations (4 ) (4 ) Miscellaneous expense (2 ) — Total Other Income, Net $ 11 $ 6 (a) For the three months ended March 31, 2019 and 2018, the non-service cost components of net periodic benefit income were partially offset by a $7 million and $4 million deferral, respectively, due to a regulatory tracking mechanism for the difference between the level of such costs incurred by Ameren Missouri under GAAP and the level of such costs included in rates. |
Derivative Financial Instrument
Derivative Financial Instruments | 3 Months Ended |
Mar. 31, 2019 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
DERIVATIVE FINANCIAL INSTRUMENTS | DERIVATIVE FINANCIAL INSTRUMENTS We use derivatives to manage the risk of changes in market prices for natural gas and power, as well as the risk of changes in rail transportation surcharges through fuel oil hedges. Such price fluctuations may cause the following: • an unrealized appreciation or depreciation of our contracted commitments to purchase or sell when purchase or sale prices under the commitments are compared with current commodity prices; • market values of natural gas inventories that differ from the cost of those commodities in inventory; and • actual cash outlays for the purchase of these commodities that differ from anticipated cash outlays. The derivatives that we use to hedge these risks are governed by our risk management policies for forward contracts, futures, options, and swaps. Our net positions are continually assessed within our structured hedging programs to determine whether new or offsetting transactions are required. The goal of the hedging program is generally to mitigate financial risks while ensuring that sufficient volumes are available to meet our requirements. Contracts we enter into as part of our risk management program may be settled financially, settled by physical delivery, or net settled with the counterparty. The following table presents open gross commodity contract volumes by commodity type for derivative assets and liabilities as of March 31, 2019 , and December 31, 2018 . As of March 31, 2019 , these contracts extended through October 2022, October 2023, and May 2032 for fuel oils, natural gas, and power, respectively. Quantity (in millions) 2019 2018 Commodity Ameren Missouri Ameren Illinois Ameren Ameren Missouri Ameren Illinois Ameren Fuel oils (in gallons) (a) 65 — 65 66 — 66 Natural gas (in mmbtu) 18 156 174 19 154 173 Power (in megawatthours) 2 8 10 1 8 9 (a) Consists of ultra-low-sulfur diesel products. All contracts considered to be derivative instruments are required to be recorded on the balance sheet at their fair values, unless the NPNS exception applies. See Note 7 – Fair Value Measurements for discussion of our methods of assessing the fair value of derivative instruments. Many of our physical contracts, such as our purchased power contracts, qualify for the NPNS exception to derivative accounting rules. The revenue or expense on NPNS contracts is recognized at the contract price upon physical delivery. If we determine that a contract meets the definition of a derivative and is not eligible for the NPNS exception, we review the contract to determine whether the resulting gains or losses qualify for regulatory deferral. Derivative contracts that qualify for regulatory deferral are recorded at fair value, with changes in fair value recorded as regulatory assets or liabilities in the period in which the change occurs. We believe derivative losses and gains deferred as regulatory assets and liabilities are probable of recovery, or refund, through future rates charged to customers. Regulatory assets and liabilities are amortized to operating income as related losses and gains are reflected in rates charged to customers. Therefore, gains and losses on these derivatives have no effect on operating income. As of March 31, 2019 , and December 31, 2018 , all contracts that met the definition of a derivative and were not eligible for the NPNS exception received regulatory deferral. The following table presents the carrying value and balance sheet location of all derivative commodity contracts, none of which were designated as hedging instruments, as of March 31, 2019 , and December 31, 2018 : March 31, 2019 December 31, 2018 Balance Sheet Location Ameren Missouri Ameren Illinois Ameren Ameren Missouri Ameren Illinois Ameren Fuel oils Other current assets $ 5 $ — $ 5 $ 3 $ — $ 3 Other assets 4 — 4 5 — 5 Natural gas Other current assets — 3 3 — 1 1 Other assets — 3 3 — 2 2 Power Other current assets 1 — 1 4 — 4 Other assets 1 — 1 — — — Total assets $ 11 $ 6 $ 17 $ 12 $ 3 $ 15 Fuel oils Other current liabilities $ 3 $ — $ 3 $ 4 $ — $ 4 Other deferred credits and liabilities 4 — 4 9 — 9 Natural gas Other current liabilities 2 6 8 4 8 12 Other deferred credits and liabilities 1 4 5 1 6 7 Power Other current liabilities 2 14 16 4 14 18 Other deferred credits and liabilities — 170 170 — 169 169 Total liabilities $ 12 $ 194 $ 206 $ 22 $ 197 $ 219 The Ameren Companies elect to present the fair value amounts of derivative assets and derivative liabilities subject to an enforceable master netting arrangement or similar agreement at the gross amounts on the balance sheet. However, if the gross amounts recognized on the balance sheet were netted with derivative instruments and cash collateral received or posted, the net amounts would not be materially different from the gross amounts at March 31, 2019 , and December 31, 2018 . Concentrations of Credit Risk In determining our concentrations of credit risk related to derivative instruments, we review our individual counterparties and categorize each counterparty into groupings according to the primary business in which each engages. We calculate maximum exposures based on the gross fair value of financial instruments, including NPNS and other accrual contracts. These exposures are calculated on a gross basis, which include affiliate exposure not eliminated at the consolidated Ameren level. As of March 31, 2019 , if counterparty groups were to fail completely to perform on contracts, the Ameren Companies’ maximum exposure would have been immaterial with or without consideration of the application of master netting arrangements or similar agreements and collateral held. Derivative Instruments with Credit Risk-related Contingent Features Our commodity contracts contain collateral provisions tied to the Ameren Companies’ credit ratings. If our credit ratings were downgraded below investment grade, or if a counterparty with reasonable grounds for uncertainty regarding our ability to satisfy an obligation requested adequate assurance of performance, additional collateral postings might be required. The following table presents, as of March 31, 2019 , the aggregate fair value of all derivative instruments with credit risk-related contingent features in a gross liability position, the cash collateral posted, and the aggregate amount of additional collateral that counterparties could require. The additional collateral required is the net liability position allowed under the master netting arrangements or similar agreements, assuming (1) the credit risk-related contingent features underlying these arrangements were triggered on March 31, 2019 , and (2) those counterparties with rights to do so requested collateral. Aggregate Fair Value of Derivative Liabilities (a) Cash Collateral Posted Potential Aggregate Amount of Additional Collateral Required (b) Ameren Missouri $ 64 $ 4 $ 58 Ameren Illinois 39 — 29 Ameren $ 103 $ 4 $ 87 (a) Before consideration of master netting arrangements or similar agreements and including NPNS and other accrual contract exposures. (b) As collateral requirements with certain counterparties are based on master netting arrangements or similar agreements, the aggregate amount of additional collateral required to be posted is determined after consideration of the effects of such arrangements. |
Fair Value Measurements
Fair Value Measurements | 3 Months Ended |
Mar. 31, 2019 | |
Fair Value Disclosures [Abstract] | |
Fair Value Disclosures | FAIR VALUE MEASUREMENTS Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Authoritative accounting guidance provides a fair value hierarchy that prioritizes the inputs used to measure fair value. On a quarterly basis, all financial assets and liabilities carried at fair value are classified and disclosed in one of three hierarchy levels. Financial assets and liabilities are classified in their entirety according to the lowest level of input that is significant to the fair value measurement. See Note 8 – Fair Value Measurements under Part II, Item 8, of the Form 10-K for information related to hierarchy levels. We consider nonperformance risk in our valuation of derivative instruments by analyzing our own credit standing and the credit standing of our counterparties, and by considering any credit enhancements (e.g., collateral). Included in our valuation, and based on current market conditions, is a valuation adjustment for counterparty default derived from market data such as the price of credit default swaps, bond yields, and credit ratings. No material gains or losses related to valuation adjustments for counterparty default risk were recorded at Ameren, Ameren Missouri, or Ameren Illinois in the three months ended March 31, 2019 or 2018 . At March 31, 2019 , and December 31, 2018 , the counterparty default risk valuation adjustment related to derivative contracts was immaterial for Ameren, Ameren Missouri, and Ameren Illinois. The following table sets forth, by level within the fair value hierarchy, our assets and liabilities measured at fair value on a recurring basis as of March 31, 2019 , and December 31, 2018 : March 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Ameren Derivative assets – commodity contracts (a) : Fuel oils $ 2 $ — $ 7 $ 9 $ 1 $ — $ 7 $ 8 Natural gas — 3 3 6 — 2 1 3 Power — — 2 2 — 1 3 4 Total derivative assets – commodity contracts $ 2 $ 3 $ 12 $ 17 $ 1 $ 3 $ 11 $ 15 Nuclear decommissioning trust fund: Equity securities: U.S. large capitalization $ 488 $ — $ — $ 488 $ 427 $ — $ — $ 427 Debt securities: U.S. Treasury and agency securities — 151 — 151 — 148 — 148 Corporate bonds — 76 — 76 — 72 — 72 Other — 33 — 33 — 32 — 32 Total nuclear decommissioning trust fund $ 488 $ 260 $ — $ 748 (b) $ 427 $ 252 $ — $ 679 (b) Total Ameren $ 490 $ 263 $ 12 $ 765 $ 428 $ 255 $ 11 $ 694 Ameren Missouri Derivative assets – commodity contracts (a) : Fuel oils $ 2 $ — $ 7 $ 9 $ 1 $ — $ 7 $ 8 Power — — 2 2 — 1 3 4 Total derivative assets – commodity contracts $ 2 $ — $ 9 $ 11 $ 1 $ 1 $ 10 $ 12 Nuclear decommissioning trust fund: Equity securities: U.S. large capitalization $ 488 $ — $ — $ 488 $ 427 $ — $ — $ 427 Debt securities: U.S. Treasury and agency securities — 151 — 151 — 148 — 148 Corporate bonds — 76 — 76 — 72 — 72 Other — 33 — 33 — 32 — 32 Total nuclear decommissioning trust fund $ 488 $ 260 $ — $ 748 (b) $ 427 $ 252 $ — $ 679 (b) Total Ameren Missouri $ 490 $ 260 $ 9 $ 759 $ 428 $ 253 $ 10 $ 691 Ameren Illinois Derivative assets – commodity contracts (a) : Natural gas $ — $ 3 $ 3 $ 6 $ — $ 2 $ 1 $ 3 Liabilities: Ameren Derivative liabilities – commodity contracts (a) : Fuel oils $ 1 $ — $ 6 $ 7 $ 2 $ — $ 11 $ 13 Natural gas — 10 3 13 — 15 4 19 Power — — 186 186 — 1 186 187 Total Ameren $ 1 $ 10 $ 195 $ 206 $ 2 $ 16 $ 201 $ 219 Ameren Missouri Derivative liabilities – commodity contracts (a) : Fuel oils $ 1 $ — $ 6 $ 7 $ 2 $ — $ 11 $ 13 Natural gas — 3 — 3 — 5 — 5 Power — — 2 2 — 1 3 4 Total Ameren Missouri $ 1 $ 3 $ 8 $ 12 $ 2 $ 6 $ 14 $ 22 Ameren Illinois Derivative liabilities – commodity contracts (a) : Natural gas $ — $ 7 $ 3 $ 10 $ — $ 10 $ 4 $ 14 Power — — 184 184 — — 183 183 Total Ameren Illinois $ — $ 7 $ 187 $ 194 $ — $ 10 $ 187 $ 197 (a) The derivative asset and liability balances are presented net of registrant and counterparty credit considerations. (b) Balance excludes $6 million and $5 million of cash and cash equivalents, receivables, payables, and accrued income, net, for March 31, 2019 , and December 31, 2018 , respectively. Level 3 fuel oils and natural gas derivative contract assets and liabilities measured at fair value on a recurring basis were immaterial for all periods presented. The following table presents the fair value reconciliation of Level 3 power derivative contract assets and liabilities measured at fair value on a recurring basis for the three months ended March 31, 2019 and 2018 : 2019 2018 Ameren Missouri Ameren Illinois Ameren Ameren Missouri Ameren Illinois Ameren Beginning balance at January 1 $ — $ (183 ) $ (183 ) $ 7 $ (195 ) $ (188 ) Realized and unrealized losses included in regulatory assets/liabilities — (4 ) (4 ) (2 ) 1 (1 ) Settlements — 3 3 (1 ) 3 2 Ending balance at March 31 $ — $ (184 ) $ (184 ) $ 4 $ (191 ) $ (187 ) Change in unrealized losses related to assets/liabilities held at March 31 $ — $ (4 ) $ (4 ) $ (1 ) $ 1 $ — For the three months ended March 31, 2019 and 2018 , there were no material transfers between Level 1 and Level 2, Level 1 and Level 3, or Level 2 and Level 3 related to derivative commodity contracts. All gains or losses related to our Level 3 derivative commodity contracts are expected to be recovered or returned through customer rates; therefore, there is no impact to net income resulting from changes in the fair value of these instruments. The following table describes the valuation techniques and significant unobservable inputs utilized for the fair value of our Level 3 power derivative contract assets and liabilities as of March 31, 2019 , and December 31, 2018 : Fair Value (a) Weighted Average Commodity Assets Liabilities Valuation Technique(s) Unobservable Input Range 2019 Power (b) $ 2 $ (186) Discounted cash flow Average forward peak and off-peak pricing – forwards/swaps ($/MWh) (c) 24 – 38 28 Nodal basis ($/MWh) (c) (9) – 0 (2) Fundamental energy production model Estimated future natural gas prices ($/mmbtu) (c) 3 – 4 3 2018 Power (b) $ 3 $ (186) Discounted cash flow Average forward peak and off-peak pricing – forwards/swaps ($/MWh) (c) 23 – 39 28 Nodal basis ($/MWh) (c) (9) – 0 (2) Fundamental energy production model Estimated future natural gas prices ($/mmbtu) (c) 3 – 4 3 (a) The derivative asset and liability balances are presented net of registrant and counterparty credit considerations. (b) Power valuations use visible third-party pricing evaluated by month for peak and off-peak demand through 2022. Valuations beyond 2022 use fundamentally modeled pricing by month for peak and off-peak demand. (c) Generally, significant increases (decreases) in this input in isolation would result in a significantly higher (lower) fair value measurement. The following table sets forth, by level within the fair value hierarchy, the carrying amount and fair value of financial assets and liabilities disclosed, but not carried, at fair value as of March 31, 2019 , and December 31, 2018 : March 31, 2019 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total Ameren: Cash, cash equivalents, and restricted cash $ 118 $ 118 $ — $ — $ 118 Investments in held-to-maturity debt securities (a) 270 — 270 — 270 Short-term debt 799 — 799 — 799 Long-term debt (including current portion) (a) 8,557 (b) — 8,623 447 (c) 9,070 Ameren Missouri: Cash, cash equivalents, and restricted cash $ 12 $ 12 $ — $ — $ 12 Investments in held-to-maturity debt securities (a) 270 — 270 — 270 Short-term debt 55 — 55 — 55 Long-term debt (including current portion) (a) 4,116 (b) — 4,404 — 4,404 Ameren Illinois: Cash, cash equivalents, and restricted cash $ 93 $ 93 $ — $ — $ 93 Short-term debt 126 — 126 — 126 Long-term debt (including current portion) 3,296 (b) — 3,515 — 3,515 December 31, 2018 Ameren: Cash, cash equivalents, and restricted cash $ 107 $ 107 $ — $ — $ 107 Investments in held-to-maturity debt securities (a) 270 — 270 — 270 Short-term debt 597 — 597 — 597 Long-term debt (including current portion) (a) 8,439 (b) — 8,240 429 (c) 8,669 Ameren Missouri: Cash, cash equivalents, and restricted cash $ 8 $ 8 $ — $ — $ 8 Investments in held-to-maturity debt securities (a) 270 — 270 — 270 Short-term debt 55 — 55 — 55 Long-term debt (including current portion) (a) 3,998 (b) — 4,156 — 4,156 Ameren Illinois: Cash, cash equivalents, and restricted cash $ 80 $ 80 $ — $ — $ 80 Short-term debt 72 — 72 — 72 Long-term debt (including current portion) 3,296 (b) — 3,391 — 3,391 (a) Ameren and Ameren Missouri have investments in industrial development revenue bonds, classified as held-to-maturity and recorded in “Other Assets,” that are equal to the finance obligations for the Peno Creek and Audrain CT energy centers. As of March 31, 2019 , and December 31, 2018 , the carrying amount of both the investments in industrial development revenue bonds and the finance obligations approximated fair value. (b) Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $62 million , $25 million , and $32 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of March 31, 2019 . Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $58 million , $22 million , and $31 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of December 31, 2018 . (c) The Level 3 fair value amount consists of ATXI’s senior unsecured notes. |
Related Party Transactions
Related Party Transactions | 3 Months Ended |
Mar. 31, 2019 | |
Related Party Transactions [Abstract] | |
RELATED PARTY TRANSACTIONS | RELATED-PARTY TRANSACTIONS In the normal course of business, Ameren Missouri and Ameren Illinois have engaged in, and may in the future engage in, affiliate transactions. These transactions primarily consist of natural gas and power purchases and sales, services received or rendered, and borrowings and lendings. Transactions between Ameren’s subsidiaries are reported as affiliate transactions on their individual financial statements, but those transactions are eliminated in consolidation for Ameren’s consolidated financial statements. For a discussion of material related-party agreements and money pool arrangements, see Note 13 – Related-party Transactions and Note 4 – Short-term Debt and Liquidity under Part II, Item 8, of the Form 10-K. Electric Power Supply Agreement In April 2019, Ameren Illinois conducted a procurement event, administered by the IPA, to purchase energy products. Ameren Missouri was among the winning suppliers in this event. As a result, in April 2019, Ameren Missouri and Ameren Illinois entered into an energy product agreement by which Ameren Missouri agreed to sell, and Ameren Illinois agreed to purchase, 288,000 megawatthours at an average price of $35 per megawatthour during the period of January 2020 through December 2021. The following table presents the impact on Ameren Missouri and Ameren Illinois of related-party transactions for the three months ended March 31, 2019 and 2018 : Three Months Agreement Income Statement Line Item Ameren Missouri Ameren Illinois Ameren Missouri power supply Operating Revenues 2019 $ (b) $ (a) agreements with Ameren Illinois 2018 3 (a) Ameren Missouri and Ameren Illinois Operating Revenues 2019 7 1 rent and facility services 2018 5 1 Ameren Missouri and Ameren Illinois Operating Revenues 2019 (b) (b) miscellaneous support services 2018 (b) (b) Total Operating Revenues 2019 $ 7 $ 1 2018 8 1 Ameren Illinois power supply Purchased Power 2019 $ (a) $ (b) agreements with Ameren Missouri 2018 (a) 3 Ameren Illinois transmission Purchased Power 2019 (a) (b) services with ATXI 2018 (a) (b) Total Purchased Power 2019 $ (a) $ (b) 2018 (a) 3 Ameren Missouri and Ameren Illinois Other Operations and Maintenance 2019 $ (b) $ 1 rent and facility services 2018 (b) 2 Ameren Services support services Other Operations and Maintenance 2019 32 30 agreement 2018 33 30 Total Other Operations and Maintenance 2019 $ 32 $ 31 2018 33 32 Money pool borrowings (advances) Interest Charges/ Other Income, Net 2019 $ — $ — 2018 (b) (b) (a) Not applicable. (b) Amount less than $1 million. |
Commitments And Contingencies
Commitments And Contingencies | 3 Months Ended |
Mar. 31, 2019 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | COMMITMENTS AND CONTINGENCIES We are involved in legal, tax, and regulatory proceedings before various courts, regulatory commissions, authorities, and governmental agencies with respect to matters that arise in the ordinary course of business, some of which involve substantial amounts of money. We believe that the final disposition of these proceedings, except as otherwise disclosed in the notes to our financial statements in this report and in the Form 10-K, will not have a material adverse effect on our results of operations, financial position, or liquidity. Reference is made to Note 1 – Summary of Significant Accounting Policies, Note 2 – Rate and Regulatory Matters, Note 13 – Related-party Transactions, and Note 14 – Commitments and Contingencies under Part II, Item 8, of the Form 10-K. See also Note 1 – Summary of Significant Accounting Policies, Note 2 – Rate and Regulatory Matters, Note 8 – Related-party Transactions, and Note 10 – Callaway Energy Center of this report. Other Obligations To supply a portion of the fuel requirements of Ameren Missouri’s energy centers, Ameren Missouri has entered into various long-term commitments for the procurement of coal, natural gas, nuclear fuel, and methane gas. Ameren Missouri and Ameren Illinois also have entered into various long-term commitments for purchased power and natural gas for distribution. The table below presents our estimated minimum fuel, purchased power, and other commitments at March 31, 2019 . Ameren’s and Ameren Illinois’ purchased power commitments include the Ameren Illinois agreements entered into as part of the IPA-administered power procurement process. Included in the Other column are minimum purchase commitments under contracts for equipment, design and construction, and meter reading services, among other agreements, at March 31, 2019 . Coal Natural Gas (a) Nuclear Fuel Purchased Power (b)(c) Methane Gas Other Total Ameren: 2019 $ 279 $ 154 $ 25 $ 88 (d) $ 2 $ 52 $ 600 2020 160 158 43 54 3 42 460 2021 121 85 58 10 3 30 307 2022 72 32 13 — 3 26 146 2023 — 8 41 — 3 29 81 Thereafter — 34 29 — 27 71 161 Total $ 632 $ 471 $ 209 $ 152 $ 41 $ 250 $ 1,755 Ameren Missouri: 2019 $ 279 $ 33 $ 25 $ — $ 2 $ 39 $ 378 2020 160 34 43 — 3 29 269 2021 121 16 58 — 3 25 223 2022 72 5 13 — 3 26 119 2023 — 5 41 — 3 29 78 Thereafter — 13 29 — 27 55 124 Total $ 632 $ 106 $ 209 $ — $ 41 $ 203 $ 1,191 Ameren Illinois: 2019 $ — $ 121 $ — $ 88 (d) $ — $ 5 $ 214 2020 — 124 — 54 — 4 182 2021 — 69 — 10 — — 79 2022 — 27 — — — — 27 2023 — 3 — — — — 3 Thereafter — 21 — — — — 21 Total $ — $ 365 $ — $ 152 $ — $ 9 $ 526 (a) Includes amounts for generation and for distribution. (b) The purchased power amounts for Ameren and Ameren Illinois exclude agreements for renewable energy credits through 2034 with various renewable energy suppliers due to the contingent nature of the payment amounts. (c) The purchased power amounts for Ameren and Ameren Missouri exclude a 102 -megawatt power purchase agreement with a wind farm operator, which expires in 2024, due to the contingent nature of the payment amounts. (d) In January 2018, as required by the FEJA, Ameren Illinois entered into 10-year agreements to acquire zero emission credits. Annual zero emission credit commitment amounts will be published by the IPA each May prior to the start of the subsequent planning year. The amounts above reflect Ameren Illinois’ commitment to acquire approximately $10 million of zero emission credits through May 2019. In April 2019, Ameren Illinois conducted procurement events, administered by the IPA, to purchase energy products through May 2022. In the April 2019 procurement event, Ameren Illinois contracted to purchase 3,704,000 megawatthours of energy products for $108 million from June 2019 through May 2022. See Note 8 – Related-party Transactions for additional information regarding energy product agreements between Ameren Missouri and Ameren Illinois as a result of the April procurement event. Environmental Matters We are subject to various environmental laws, including statutes and regulations, enforced by federal, state, and local authorities. The development and operation of electric generation, transmission, and distribution facilities and natural gas storage, transmission, and distribution facilities can trigger compliance obligations with respect to environmental laws. These laws address emissions, discharges to water, water intake, impacts to air, land, and water, and chemical and waste handling. Complex and lengthy processes are required to obtain and renew approvals, permits, and licenses for new, existing or modified facilities. Additionally, the use and handling of various chemicals or hazardous materials require release prevention plans and emergency response procedures. The EPA has promulgated environmental regulations that have a significant impact on the electric utility industry. Over time, compliance with these regulations could be costly for Ameren Missouri, which operates coal-fired power plants. As of December 31, 2018, Ameren Missouri’s fossil fuel-fired energy centers represented 16% and 32% of Ameren’s and Ameren Missouri’s rate base, respectively. Regulations that apply to air emissions from the electric utility industry include the NSPS, the CSAPR, the MATS, and the National Ambient Air Quality Standards, which are subject to periodic review for certain pollutants. Collectively, these regulations cover a variety of pollutants, such as SO 2 , particulate matter, NO x , mercury, toxic metals, and acid gases, and CO 2 emissions from new power plants. Water intake and discharges from power plants are regulated under the Clean Water Act. Such regulation could require modifications to water intake structures or more stringent limitations on wastewater discharges at Ameren Missouri’s energy centers, either of which could result in significant capital expenditures. The management and disposal of coal ash is regulated under the CCR rule, which will require the closure of surface impoundments and the installations of dry ash handling systems at several of Ameren Missouri’s energy centers. The individual or combined effects of existing environmental regulations could result in significant capital expenditures, increased operating costs, or the closure or alteration of operations at some of Ameren Missouri’s energy centers. Ameren and Ameren Missouri expect that such compliance costs would be recoverable through rates, subject to MoPSC prudence review, but the timing of costs and their recovery could be subject to regulatory lag. Ameren and Ameren Missouri estimate that they will need to make capital expenditures of $300 million to $400 million from 2019 through 2023 in order to comply with existing environmental regulations. Additional environmental controls beyond 2023 could be required. This estimate of capital expenditures includes expenditures required by the CCR regulations, by the Clean Water Act rule applicable to cooling water intake structures at existing power plants, and by effluent limitation guidelines applicable to steam electric generating units, all of which are discussed below. Ameren Missouri’s current plan for compliance with existing air emission regulations includes burning ultra-low-sulfur coal and installing new or optimizing existing pollution control equipment. The actual amount of capital expenditures required to comply with existing environmental regulations may vary substantially from the above estimate because of uncertainty as to whether the EPA will substantially revise regulatory obligations, exactly which compliance strategies will be used and their ultimate cost, among other things. The following sections describe the more significant environmental laws and rules and environmental enforcement and remediation matters that affect or could affect our operations. The EPA has initiated an administrative review of several regulations and proposed amendments to regulations and guidelines, including to the effluent limitation guidelines and the CCR Rule, which could ultimately result in the revision of all or part of such rules. Clean Air Act Federal and state laws, including CSAPR, regulate emissions of SO 2 and NO x through emission source reductions and the use and retirement of emission allowances. The first phase of the CSAPR emission reduction requirements became effective in 2015. The second phase of emission reduction requirements, which were revised by the EPA in 2016, became effective in 2017; additional emission reduction requirements may apply in subsequent years. To achieve compliance with the CSAPR, Ameren Missouri burns ultra-low-sulfur coal, operates two scrubbers at its Sioux energy center, and optimizes other existing pollution control equipment. Ameren Missouri expects to incur additional costs to lower its emissions at one or more of its energy centers to comply with the CSAPR in future years. These higher costs are expected to be recovered from customers through the FAC or higher base rates. CO 2 Emissions Standards In 2015, the EPA issued the Clean Power Plan, which would have established CO 2 emissions standards applicable to existing power plants. The United States Supreme Court stayed the rule in February 2016, pending various legal challenges. In August 2018, the EPA proposed to repeal and replace the Clean Power Plan with a proposed new rule known as the Affordable Clean Energy Rule, which establishes emission guidelines for states to follow in developing plans to limit CO 2 emissions from power plants. The EPA proposes to use certain efficiency measures as the best system of emission reduction for coal-fired power plants. The EPA is expected to finalize the Affordable Clean Energy rule in the first half of 2019. We cannot predict the outcome of EPA’s rulemaking or the outcome of legal challenges related to such rulemaking. NSR and Clean Air Litigation In January 2011, the Department of Justice, on behalf of the EPA, filed a complaint against Ameren Missouri in the United States District Court for the Eastern District of Missouri. The complaint, as amended in October 2013, alleged that in performing projects at its Rush Island coal-fired energy center in 2007 and 2010, Ameren Missouri violated provisions of the Clean Air Act and Missouri law. The litigation has been divided into two phases: liability and remedy. In the first phase, in January 2017, the district court issued a liability ruling that the projects violated provisions of the Clean Air Act and Missouri law. In the second phase, the district court will determine the actions required to remedy the violations found in the liability phase. The EPA previously withdrew all claims for penalties and fines. A trial on the scope of the appropriate remedy occurred in April 2019, and a final ruling from the court is expected by the end of 2019. Once the court issues its final order and judgment, Ameren Missouri will seek a stay of that order while it seeks an appeal of the liability ruling to the United States Court of Appeals for the Eighth Circuit. The ultimate resolution of this matter could have a material adverse effect on the results of operations, financial position, and liquidity of Ameren and Ameren Missouri. Among other things and subject to economic and regulatory considerations, resolution of this matter could result in increased capital expenditures for the installation of pollution control equipment, as well as increased operations and maintenance expenses. We are unable to predict the ultimate resolution of this matter or the costs that might be incurred. Clean Water Act In July 2018, the United States Court of Appeals for the Second Circuit upheld the EPA’s Section 316(b) Rule applicable to cooling water intake structures at existing power plants. The rule requires a case-by-case evaluation and plan for reducing aquatic organisms impinged on a power plant’s cooling water intake screens or entrained through the plant’s cooling water system. All of Ameren Missouri’s coal-fired and nuclear energy centers are subject to the cooling water intake structures rule. The rule will be implemented by Ameren Missouri during the permit renewal process of each energy center’s water discharge permit, which is expected to be completed by 2023. In 2015, the EPA issued a rule to revise the effluent limitation guidelines applicable to steam electric generating units. These guidelines established national standards for water discharges that are based on the effectiveness of available control technology. The EPA’s 2015 rule prohibits effluent discharges of certain waste streams and imposes more stringent limitations on certain water discharges from power plants. In September 2017, the EPA published a rule that postponed the compliance dates by two years for the limitations applicable to two specific waste streams so that it could potentially revise those standards. Ameren Missouri is in the process of constructing wastewater treatment facilities that meet the limitations in these guidelines at three of its energy centers. CCR Management In 2015, the EPA issued the CCR rule, which established regulations regarding the management and disposal of CCR from coal-fired energy centers. These regulations affect CCR disposal and handling costs at Ameren Missouri’s energy centers. Ameren Missouri is in the process of closing its surface impoundments and anticipates the last of such CCR storage facilities to be closed by 2023. In July 2018, the EPA issued revisions to the CCR rule and indicated that additional revisions to the CCR rule are likely. Ameren and Ameren Missouri have AROs of $131 million recorded on their respective balance sheets as of March 31, 2019 , associated with CCR storage facilities that reflect the regulations issued in 2015. Ameren Missouri estimates it will need to make capital expenditures of $150 million to $200 million from 2019 through 2023 to implement its CCR management compliance plan, which includes installation of dry ash handling systems, waste water treatment facilities, and groundwater monitoring equipment. Remediation The Ameren Companies are involved in a number of remediation actions to clean up sites impacted by the use or disposal of materials containing hazardous substances. Federal and state laws can require responsible parties to fund remediation regardless of their degree of fault, the legality of original disposal, or the ownership of a disposal site. Ameren Missouri and Ameren Illinois have each been identified by federal or state governments as a potentially responsible party at several contaminated sites. As of March 31, 2019 , Ameren Illinois has remediated the majority of the 44 former MGP sites in Illinois it owned or for which it was otherwise responsible. Ameren Illinois estimates it could substantially conclude remediation efforts at its remaining sites by 2023. The ICC allows Ameren Illinois to recover such remediation and related litigation costs from its electric and natural gas utility customers through environmental cost riders. Costs are subject to annual prudence review by the ICC. As of March 31, 2019 , Ameren Illinois estimated the obligation related to these former MGP sites at $145 million to $215 million . Ameren and Ameren Illinois recorded a liability of $145 million to represent the estimated minimum obligation for these sites, as no other amount within the range was a better estimate. The scope of the remediation activities at these former MGP sites may increase as remediation efforts continue. Considerable uncertainty remains in these estimates because many site-specific factors can influence the ultimate actual costs, including unanticipated underground structures, the degree to which groundwater is encountered, regulatory changes, local ordinances, and site accessibility. The actual costs and timing of completion may vary substantially from these estimates. Our operations or those of our predecessor companies involve the use of, disposal of, and, in appropriate circumstances, the cleanup of substances regulated under environmental laws. We are unable to determine whether such practices will result in future environmental commitments or will affect our results of operations, financial position, or liquidity. |
Callaway Energy Center
Callaway Energy Center | 3 Months Ended |
Mar. 31, 2019 | |
Nuclear Waste Matters [Abstract] | |
CALLAWAY ENERGY CENTER | CALLAWAY ENERGY CENTER Decommissioning Electric rates charged to customers provide for the recovery of the Callaway energy center’s decommissioning costs, which include decontamination, dismantling, and site restoration costs, over the expected life of the nuclear energy center. Amounts collected from customers are deposited into the external nuclear decommissioning trust fund to provide for the Callaway energy center’s decommissioning. It is assumed that the Callaway energy center site will be decommissioned through the immediate dismantlement method and removed from service. Ameren and Ameren Missouri have recorded an ARO for the Callaway energy center decommissioning costs at fair value, which represents the present value of estimated future cash outflows. Annual decommissioning costs of $7 million are included in the costs used to establish electric rates for Ameren Missouri’s customers. The fair value of the trust fund for Ameren Missouri’s Callaway energy center is reported as “Nuclear decommissioning trust fund” in Ameren’s and Ameren Missouri’s balance sheets. This amount is legally restricted and may be used only to fund the costs of nuclear decommissioning. Changes in the fair value of the trust fund are recorded as an increase or decrease to the nuclear decommissioning trust fund, with an offsetting adjustment to the related regulatory liability. If the assumed return on trust assets is not earned, Ameren Missouri believes that it is probable that any such earnings deficiency will be recovered in rates. Insurance The following table presents insurance coverage at Ameren Missouri’s Callaway energy center as of April 1, 2019. The property coverage and the nuclear liability coverage renewal dates are April 1 and January 1, respectively, of each year. Both coverages were renewed in 2019. Type and Source of Coverage Maximum Coverages Maximum Assessments for Single Incidents Public liability and nuclear worker liability: American Nuclear Insurers $ 450 $ — Pool participation 13,623 (a) 138 (b) $ 14,073 (c) $ 138 Property damage: NEIL and EMANI $ 3,200 (d) $ 28 (e) Replacement power: NEIL $ 490 (f) $ 7 (e) (a) Provided through mandatory participation in an industrywide retrospective premium assessment program. The maximum coverage available is dependent on the number of United States commercial reactors participating in the program. (b) Retrospective premium under the Price-Anderson Act. This is subject to retrospective assessment with respect to a covered loss in excess of $450 million in the event of an incident at any licensed United States commercial reactor, payable at $21 million per year. (c) Limit of liability for each incident under the Price-Anderson liability provisions of the Atomic Energy Act of 1954, as amended. This limit is subject to change to account for the effects of inflation and changes in the number of licensed reactors. (d) NEIL provides $2.7 billion in property damage, stabilization, decontamination, and premature decommissioning insurance for radiation events and $2.3 billion in property damage insurance for nonradiation events. EMANI provides $490 million in property damage insurance for both radiation and nonradiation events. (e) All NEIL insured plants could be subject to assessments should losses exceed the accumulated funds from NEIL. (f) Provides replacement power cost insurance in the event of a prolonged accidental outage. Weekly indemnity up to $4.5 million for 52 weeks, which commences after the first twelve weeks of an outage, plus up to $3.6 million per week for a minimum of 71 weeks thereafter for a total not exceeding the policy limit of $490 million . Nonradiation events are limited to $328 million . The Price-Anderson Act is a federal law that limits the liability for claims from an incident involving any licensed United States commercial nuclear energy center. The limit is based on the number of licensed reactors. The limit of liability and the maximum potential annual payments are adjusted at least every five years for inflation to reflect changes in the Consumer Price Index. The most recent five-year inflationary adjustment became effective in November 2018. Owners of nuclear reactors cover this exposure through a combination of private insurance and mandatory participation in a financial protection pool, as established by the Price-Anderson Act. Losses resulting from terrorist attacks on nuclear facilities insured by NEIL are subject to industrywide aggregates, such that terrorist acts against one or more commercial nuclear power plants within a stated time period would be treated as a single event, and the owners of the nuclear power plants would share the limit of liability. NEIL policies have an aggregate limit of $3.2 billion within a 12-month period for radiation events, or $1.8 billion for events not involving radiation contamination. The EMANI policies are not subject to industrywide aggregates in the event of terrorist attacks on nuclear facilities. If losses from a nuclear incident at the Callaway energy center exceed the limits of, or are not covered by insurance, or if coverage is unavailable, Ameren Missouri is at risk for any uninsured losses. If a serious nuclear incident were to occur, it could have a material adverse effect on Ameren’s and Ameren Missouri’s results of operations, financial position, or liquidity. |
Retirement Benefits
Retirement Benefits | 3 Months Ended |
Mar. 31, 2019 | |
Defined Benefit Plan [Abstract] | |
RETIREMENT BENEFITS | RETIREMENT BENEFITS The following table presents the components of the net periodic benefit cost (income) incurred for Ameren’s pension and postretirement benefit plans for the three months ended March 31, 2019 and 2018 : Pension Benefits Postretirement Benefits Three Months Three Months 2019 2018 2019 2018 Service cost (a) $ 22 $ 25 $ 4 $ 5 Non-service cost components: Interest cost 47 42 11 11 Expected return on plan assets (69 ) (69 ) (19 ) (19 ) Amortization of: Prior service benefit — — (1 ) (1 ) Actuarial loss (gain) 6 16 (4 ) — Total non-service cost components (b) $ (16 ) $ (11 ) $ (13 ) $ (9 ) Net periodic benefit cost (income) $ 6 $ 14 $ (9 ) $ (4 ) (a) Service cost, net of capitalization, is reflected in “Operating Expenses – Other operations and maintenance” on Ameren’s statement of income. (b) Non-service cost components are reflected in “Other Income, Net” on Ameren’s statement of income. See Note 5 – Other Income, Net for additional information. Ameren Missouri and Ameren Illinois are responsible for their respective shares of Ameren’s pension and postretirement costs. The following table presents the respective share of net periodic pension and other postretirement benefit costs (income) incurred for the three months ended March 31, 2019 and 2018 : Pension Benefits Postretirement Benefits Three Months Three Months 2019 2018 2019 2018 Ameren Missouri (a) $ 1 $ 5 $ (2 ) $ — Ameren Illinois 5 9 (7 ) (4 ) Ameren (a) $ 6 $ 14 $ (9 ) $ (4 ) (a) Does not include the impact of the regulatory tracking mechanism for the difference between the level of pension and postretirement benefit costs incurred by Ameren Missouri under GAAP and the level of such costs included in rates. |
Income Taxes
Income Taxes | 3 Months Ended |
Mar. 31, 2019 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | INCOME TAXES The following table presents a reconciliation of the federal statutory corporate income tax rate to the effective income tax rate for the three months ended March 31, 2019 and 2018 : Ameren Ameren Missouri Ameren Illinois Three Months 2019 2018 2019 2018 2019 2018 Federal statutory corporate income tax rate: 21% 21% 21% 21% 21% 21% Increases (decreases) from: Amortization of excess deferred taxes (7) (2) (a) (12) — (a) (3) (3) Other depreciation differences — — — 1 — — Amortization of deferred investment tax credit (1) (1) (1) (1) — — State tax 6 7 4 4 7 7 Stock-based compensation (7) (3) — — — — Other — — (3) — — — Effective income tax rate 12% 22% 9% 25% 25% 25% (a) Based on an order by the MoPSC in July 2018, Ameren Missouri began amortizing excess deferred taxes in August 2018. |
Supplemental Information
Supplemental Information | 3 Months Ended |
Mar. 31, 2019 | |
Supplemental Information [Abstract] | |
Supplemental Information | SUPPLEMENTAL INFORMATION Cash, Cash Equivalents, and Restricted Cash The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets and the statements of cash flows as of March 31, 2019 , and December 31, 2018 : March 31, 2019 December 31, 2018 Ameren Ameren Ameren Ameren Ameren Ameren Cash and cash equivalents $ 8 $ — $ — $ 16 $ — $ — Restricted cash included in “Other current assets” 16 5 6 13 4 6 Restricted cash included in “Other assets” 87 — 87 74 — 74 Restricted cash included in “Nuclear decommissioning trust fund” 7 7 — 4 4 — Total cash, cash equivalents, and restricted cash $ 118 $ 12 $ 93 $ 107 $ 8 $ 80 Restricted cash included in “Other current assets” primarily represents funds held by an irrevocable Voluntary Employee Beneficiary Association (VEBA) trust, which provides health care benefits for active employees. Restricted cash included in “Other assets” on Ameren’s and Ameren Illinois’ balance sheets primarily represents amounts collected under a cost recovery rider restricted for use in the procurement of renewable energy credits and amounts in a trust fund restricted for the use of funding certain asbestos-related claims. Accounts Receivable “Accounts receivable – trade” on Ameren’s and Ameren Illinois’ balance sheets include certain receivables purchased at a discount from alternative retail electric suppliers that elect to participate in the utility consolidated billing program. At March 31, 2019 , and December 31, 2018 , “Other current liabilities” on Ameren’s and Ameren Illinois’ balance sheets included payables for purchased receivables of $38 million and $33 million , respectively. For the three months ended March 31, 2019 and 2018 , the Ameren Companies recorded immaterial bad debt expense. Leases In the first quarter of 2019, we adopted authoritative accounting guidance related to leases, which affected our financial position, but did not materially affect our results of operations or liquidity. The most significant impact for us was the recognition of right-of-use assets and lease liabilities for operating leases, while the accounting for our finance leases remained substantially unchanged. Ameren and Ameren Missouri recognized right-of-use assets and offsetting lease liabilities of $38 million and $36 million at January 1, 2019, respectively, primarily related to rail car leases. The effect of the adoption was immaterial at Ameren Illinois. No adjustment to comparative periods was made. We elected the available practical expedients upon adoption. Ameren Missouri leases rail cars under operating lease arrangements for the transportation of coal inventory to its energy centers. Although Ameren Missouri has options to renew a portion of these arrangements for up to five years on similar terms, the exercise of these options was not assumed in the recognition of right-of-use assets and lease obligations. For rail car leases, we account for the lease and non-lease components as a single lease component. The operating lease expense and the cash paid for amounts included in the measurement of operating lease liabilities at Ameren and Ameren Missouri were immaterial for the three months ended March 31, 2019 and 2018 . The following table provides supplemental balance sheet information related to operating leases as of March 31, 2019 : Ameren Ameren Missouri Other assets $ 36 $ 34 Other current liabilities 7 6 Other deferred credits and liabilities 29 28 Weighted average remaining operating lease term 6 years 6 years Weighted average discount rate (a) 3.6 % 3.6 % (a) As most of our lease agreements do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. We use the implicit rate when readily determinable. The following table presents Ameren’s and Ameren Missouri’s remaining maturities of operating lease liabilities as of March 31, 2019 : Ameren Ameren Missouri 2019 $ 6 $ 5 2020 7 7 2021 7 6 2022 6 5 2023 5 5 Thereafter 10 10 Total lease payments 41 38 Less imputed interest 5 4 Total (a) $ 36 $ 34 (a) The amount of remaining maturities of operating lease liabilities under previous authoritative accounting guidance as of December 31, 2018, is materially consistent to the amount as of March 31, 2019. Maturities of certain financing arrangements, including the Peno Creek and Audrain energy centers' long-term agreements, are no longer required to be disclosed as lease-related maturities. See Note 5 - Long-Term Debt and Equity Financings under Part II, Item 8, in the Form 10-K for further information on financing arrangements. Supplemental Cash Flow Information The following table provides noncash investing activity excluded from the statements of cash flows for the three months ended March 31, 2019 and 2018 : March 31, 2019 March 31, 2018 Ameren Ameren Missouri Ameren Illinois Ameren Ameren Missouri Ameren Illinois Accrued capital expenditures $ 208 $ 92 $ 106 $ 202 $ 73 $ 114 Net realized and unrealized gain (loss) – nuclear decommissioning trust fund 64 64 — (11 ) (11 ) — Asset Retirement Obligations The following table provides a reconciliation of the beginning and ending carrying amount of AROs for the three months ended March 31, 2019 : Ameren Missouri Ameren Illinois (a) Ameren Balance at December 31, 2018 $ 646 (a) $ 4 (b) $ 650 (a) Liabilities settled (3 ) — (3 ) Accretion 6 (c) — 6 (c) Balance at March 31, 2019 $ 649 (a) $ 4 (b) $ 653 (a) (a) Balance included $23 million in “Other current liabilities” on the balance sheet as of both December 31, 2018 , and March 31, 2019 . (b) Included in “Other deferred credits and liabilities” on the balance sheet. (c) Accretion expense attributable to Ameren Missouri was recorded as a decrease to regulatory liabilities. Stock-based Compensation The following table summarizes Ameren's nonvested performance share unit and restricted stock unit activity for the three months ended March 31, 2019 : Performance Share Units Restricted Stock Units Share Units Weighted-average Fair Value per Share Unit Stock Units Weighted-average Fair Value per Stock Unit Nonvested at January 1, 2019 (a) 682,811 $ 56.58 155,253 $ 57.38 Granted 288,956 67.42 (b) 124,925 65.23 Forfeitures (2,228 ) 65.06 (833 ) 63.16 Vested and undistributed (c) (65,458 ) 62.04 (14,047 ) 61.77 Vested and distributed (176,923 ) 44.13 — — Nonvested at March 31, 2019 (d) 727,158 $ 63.40 265,298 $ 60.64 (a) Does not include 619,783 vested and undistributed performance share units and 26,557 vested and undistributed restricted stock units. (b) Significant inputs to the Monte Carlo simulation model used to calculate the fair value of performance share units granted include Ameren’s closing common share price of $65.23 at December 31, 2018 , Ameren’s common stock volatility of 17% , a volatility range for the peer group of 15% to 25% , and a three-year risk-free rate of 2.46% . (c) Vested and undistributed units are awards that vested due to attainment of retirement eligibility by certain employees, but have not yet been distributed. For vested and undistributed performance share units, the number of shares issued for retirement-eligible employees will vary depending on actual performance over the three -year performance period. (d) Does not include 333,466 vested and undistributed performance share units and 40,604 vested and undistributed restricted stock units. For the three months ended March 31, 2019 and 2018 , excess tax benefits associated with the settlement of stock-based compensation awards reduced income tax expense by $14 million and $6 million , respectively. Deferred Compensation As of March 31, 2019 , and December 31, 2018 , “Other deferred credits and liabilities” on Ameren’s balance sheet included deferred compensation obligations of $78 million and $80 million , respectively, recorded at the present value of future benefits to be paid. Operating Revenues As of March 31, 2019 and 2018 , our remaining performance obligations for contracts with a term greater than one year were immaterial. The Ameren Companies elected not to disclose the aggregate amount of the transaction price allocated to the performance obligations that are unsatisfied as of the end of the reporting period for contracts with an initial expected term of one year or less. See Note 14 – Segment Information for disaggregated revenue information. Excise Taxes Ameren Missouri and Ameren Illinois collect from their customers excise taxes, including municipal and state excise taxes and gross receipts taxes, that are levied on the sale or distribution of natural gas and electricity. The following table presents the excise taxes recorded on a gross basis in “Operating Revenues – Electric,” “Operating Revenues – Natural gas” and “Operating Expenses – Taxes other than income taxes” on the statements of income for the three months ended March 31, 2019 and 2018 : Three Months 2019 2018 Ameren Missouri $ 31 $ 34 Ameren Illinois 39 35 (a) Ameren $ 70 $ 69 (a) (a) Amounts have been adjusted from those previously reported to reflect additional excise taxes for the three months ended March 31, 2018. Earnings per Share Earnings per basic and diluted share are computed by dividing “Net Income Attributable to Ameren Common Shareholders” by the weighted-average number of basic and diluted common shares outstanding, respectively, during the period. Earnings per diluted share reflects the dilution that would occur if certain stock-based performance share units and restricted stock units were assumed to be settled. The number of performance share units and restricted stock units assumed settled was 1.5 million for both the three months ended March 31, 2019 and 2018 . There were no potentially dilutive securities excluded from the earnings per diluted share calculations for the three months ended March 31, 2019 and 2018 . |
Segment Information
Segment Information | 3 Months Ended |
Mar. 31, 2019 | |
Segment Reporting [Abstract] | |
SEGMENT INFORMATION | SEGMENT INFORMATION Ameren has four segments: Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Transmission. The Ameren Missouri segment includes all of the operations of Ameren Missouri. Ameren Illinois Electric Distribution consists of the electric distribution business of Ameren Illinois. Ameren Illinois Natural Gas consists of the natural gas business of Ameren Illinois. Ameren Transmission primarily consists of the aggregated electric transmission businesses of Ameren Illinois and ATXI. The category called Other primarily includes Ameren (parent) activities and Ameren Services. Ameren Missouri has one segment. Ameren Illinois has three segments: Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Illinois Transmission. See Note 1 – Summary of Significant Accounting Policies for additional information regarding the operations of Ameren Missouri, Ameren Illinois, and ATXI. Segment operating revenues and a majority of operating expenses are directly recognized and incurred by Ameren Illinois at each Ameren Illinois segment. Common operating expenses, miscellaneous income and expenses, interest charges, and income tax expense are allocated by Ameren Illinois to each Ameren Illinois segment based on certain factors, which primarily relate to the nature of the cost. Additionally, Ameren Illinois Transmission earns revenue from transmission services provided to Ameren Illinois Electric Distribution, other retail electric suppliers, and wholesale customers. The transmission expense for Illinois customers who have elected to purchase their power from Ameren Illinois is recovered through a cost recovery mechanism with no net effect on Ameren Illinois Electric Distribution earnings, as costs are offset by corresponding revenues. Transmission revenues from these transactions are reflected in Ameren Transmission’s and Ameren Illinois Transmission’s operating revenues. An intersegment elimination at Ameren and Ameren Illinois occurs to eliminate these transmission revenues and expenses. The following tables present revenues, net income attributable to common shareholders, and capital expenditures by segment at Ameren and Ameren Illinois for the three months ended March 31, 2019 and 2018 . Ameren, Ameren Missouri, and Ameren Illinois management review segment capital expenditure information rather than any individual or total asset amount. Ameren Three Months Ameren Missouri Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Transmission Other Intersegment Eliminations Ameren 2019 External revenues $ 751 $ 386 $ 320 $ 99 $ — $ — $ 1,556 Intersegment revenues 7 1 — 15 — (23 ) — Net income attributable to Ameren common shareholders 39 36 57 44 (a) 15 — 191 Capital expenditures 240 124 51 121 10 (2 ) 544 2018 External revenues $ 784 $ 399 $ 311 $ 91 $ — $ — $ 1,585 Intersegment revenues 8 1 — 13 — (22 ) — Net income attributable to Ameren common shareholders 38 33 42 37 (a) 1 — 151 Capital expenditures 249 122 60 145 7 (4 ) 579 (a) Ameren Transmission earnings include an allocation of financing costs from Ameren (parent). Ameren Illinois Three Months Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Illinois Transmission Intersegment Eliminations Ameren Illinois 2019 External revenues $ 387 $ 320 $ 55 $ — $ 762 Intersegment revenues — — 15 (15 ) — Net income available to common shareholder 36 57 27 — 120 Capital expenditures 124 51 92 — 267 2018 External revenues $ 400 $ 311 $ 49 $ — $ 760 Intersegment revenues — — 13 (13 ) — Net income available to common shareholder 33 42 20 — 95 Capital expenditures 122 60 118 — 300 The following tables present disaggregated revenues by segment at Ameren and Ameren Illinois for the three months ended March 31, 2019 and 2018 . Economic factors affect the nature, timing, amount, and uncertainty of revenues and cash flows in a similar manner across customer classes. Revenues from alternative revenue programs have a similar distribution among customer classes as revenues from contracts with customers. Other revenues not associated with contracts with customers are presented in the Other customer classification, along with electric transmission and off-system revenues. Ameren Three Months Ameren Missouri Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Transmission Other Intersegment Eliminations Ameren 2019 Residential $ 312 $ 217 $ — $ — $ — $ — $ 529 Commercial 239 123 — — — — 362 Industrial 55 34 — — — — 89 Other 98 13 — 114 — (23 ) 202 Total electric revenues $ 704 $ 387 $ — $ 114 $ — $ (23 ) $ 1,182 Residential $ 38 $ — $ 246 $ — $ — $ — $ 284 Commercial 16 — 65 — — — 81 Industrial 2 — 4 — — — 6 Other (2 ) — 5 — — — 3 Total gas revenues $ 54 $ — $ 320 $ — $ — $ — $ 374 Total revenues (a) $ 758 $ 387 $ 320 $ 114 $ — $ (23 ) $ 1,556 2018 Residential $ 332 $ 219 $ — $ — $ — $ — $ 551 Commercial 252 124 — — — — 376 Industrial 61 35 — — — — 96 Other 96 22 — 104 — (22 ) 200 Total electric revenues $ 741 $ 400 $ — $ 104 $ — $ (22 ) $ 1,223 Residential $ 41 $ — $ 243 $ — $ — $ — $ 284 Commercial 16 — 67 — — — 83 Industrial 2 — 6 — — — 8 Other (8 ) — (5 ) — — — (13 ) Total gas revenues $ 51 $ — $ 311 $ — $ — $ — $ 362 Total revenues (a) $ 792 $ 400 $ 311 $ 104 $ — $ (22 ) $ 1,585 (a) The following table presents increases/(decreases) in revenues from alternative revenue programs and other revenues not from contracts with customers for the three months ended March 31, 2019 and 2018 : Three Months Ameren Missouri Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Transmission Ameren 2019 Revenues from alternative revenue programs $ 15 $ 22 $ (3 ) $ (5 ) $ 29 Other revenues not from contracts with customers 5 3 1 — 9 2018 Revenues from alternative revenue programs $ (4 ) $ 31 $ (3 ) $ (4 ) $ 20 Other revenues not from contracts with customers 14 10 1 — 25 Ameren Illinois Three Months Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Illinois Transmission Intersegment Eliminations Total Ameren Illinois 2019 Residential $ 217 $ 246 $ — $ — $ 463 Commercial 123 65 — — 188 Industrial 34 4 — — 38 Other 13 5 70 (15 ) 73 Total revenues (a) $ 387 $ 320 $ 70 $ (15 ) $ 762 2018 Residential $ 219 $ 243 $ — $ — $ 462 Commercial 124 67 — — 191 Industrial 35 6 — — 41 Other 22 (5 ) 62 (13 ) 66 Total revenues (a) $ 400 $ 311 $ 62 $ (13 ) $ 760 (a) The following table presents increases/(decreases) in revenues from alternative revenue programs and other revenues not from contracts with customers for the Ameren Illinois segments for the three months ended March 31, 2019 and 2018 : Three Months Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Illinois Transmission Ameren Illinois 2019 Revenues from alternative revenue programs $ 22 $ (3 ) $ (5 ) $ 14 Other revenues not from contracts with customers 3 1 — 4 2018 Revenues from alternative revenue programs $ 31 $ (3 ) $ (4 ) $ 24 Other revenues not from contracts with customers 10 1 — 11 |
Summary Of Significant Accoun_2
Summary Of Significant Accounting Policies (Policies) | 3 Months Ended |
Mar. 31, 2019 | |
Accounting Policies [Abstract] | |
Nature of Operations | Ameren, headquartered in St. Louis, Missouri, is a public utility holding company whose primary assets are its equity interests in its subsidiaries. Ameren’s subsidiaries are separate, independent legal entities with separate businesses, assets, and liabilities. Dividends on Ameren’s common stock and the payment of expenses by Ameren depend on distributions made to it by its subsidiaries. Ameren’s principal subsidiaries are listed below. Ameren has other subsidiaries that conduct other activities, such as providing shared services. • Union Electric Company, doing business as Ameren Missouri, operates a rate-regulated electric generation, transmission, and distribution business and a rate-regulated natural gas distribution business in Missouri. • Ameren Illinois Company, doing business as Ameren Illinois, operates rate-regulated electric transmission, electric distribution, and natural gas distribution businesses in Illinois. • ATXI operates a FERC rate-regulated electric transmission business. ATXI placed the Spoon River project in service in February 2018, and is developing two additional MISO-approved electric transmission projects, the Illinois Rivers and Mark Twain projects. |
Consolidation | Ameren’s financial statements are prepared on a consolidated basis and therefore include the accounts of its majority-owned subsidiaries. All intercompany transactions have been eliminated. Ameren Missouri and Ameren Illinois have no subsidiaries. All tabular dollar amounts are in millions, unless otherwise indicated. Our accounting policies conform to GAAP. Our financial statements reflect all adjustments (which include normal, recurring adjustments) that are necessary, in our opinion, for a fair statement of our results. The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions. Such estimates and assumptions affect reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the dates of financial statements, and the reported amounts of revenues and expenses during the reported periods. Actual results could differ from those estimates. The results of operations of an interim period may not give a true indication of results that may be expected for a full year. These financial statements should be read in conjunction with the financial statements and accompanying notes included in the Form 10-K. Variable Interest Entities As of March 31, 2019 , Ameren and Ameren Missouri had interests in unconsolidated variable interest entities that were established to construct wind generation facilities and, ultimately, sell those constructed facilities to Ameren Missouri. Neither Ameren nor Ameren Missouri are the primary beneficiary of these variable interest entities because neither has the power to direct matters that most significantly affect the entities' activities, which include designing, financing, and constructing the wind generation facilities. As a result, these variable interest entities have not been consolidated. As of March 31, 2019 , the maximum exposure to loss related to these variable interest entities was approximately $16 million , which represents the portion of interconnection study costs that may be incurred by Ameren and Ameren Missouri. The risk of a loss was assessed to be remote and, accordingly, Ameren and Ameren Missouri have not recognized a liability associated with any portion of the maximum exposure to loss. See Note 2 – Rate and Regulatory Matters for additional information on the agreements to acquire these wind generation facilities. As of March 31, 2019 , and December 31, 2018 , Ameren had unconsolidated variable interests as a limited partner in various equity method investments, totaling $23 million and $22 million , respectively, included in “Other assets” on Ameren’s consolidated balance sheet. Ameren is not the primary beneficiary of these investments because it does not have the power to direct matters that most significantly affect the activities of these variable interest entities. As of March 31, 2019 , the maximum exposure to loss related to these variable interests is limited to the investment in these partnerships of $23 million plus associated outstanding funding commitments of $15 million . |
Company-owned Life Insurance | Company-owned Life Insurance Ameren and Ameren Illinois have company-owned life insurance, which is recorded at the net cash surrender value. The net cash surrender value is the amount that can be realized under the insurance policies at the balance sheet date. As of March 31, 2019 , the cash surrender value of company-owned life insurance at Ameren and Ameren Illinois was $ 258 million ( December 31, 2018 – $244 million ) and $ 123 million ( December 31, 2018 – $122 million ), respectively, while total borrowings against the policies were $ 113 million ( December 31, 2018 – $113 million ) at both Ameren and Ameren Illinois. Ameren and Ameren Illinois have the right to offset the borrowings against the cash surrender value of the policies and, consequently, present the net asset in “Other assets” on their respective balance sheets. |
Accounting and Reporting Developments | Accounting and Reporting Developments See Note 13 – Supplemental Information for additional information on our adoption of authoritative accounting guidance related to leases. See Note 1 – Summary of Significant Accounting Policies under Part II, Item 8, of the Form 10-K for additional information about recently issued authoritative accounting standards relating to the measurement of credit losses on financial instruments, fair value measurement disclosures, and defined benefit plan disclosures. |
Derivatives, Policy | The Ameren Companies elect to present the fair value amounts of derivative assets and derivative liabilities subject to an enforceable master netting arrangement or similar agreement at the gross amounts on the balance sheet. We use derivatives to manage the risk of changes in market prices for natural gas and power, as well as the risk of changes in rail transportation surcharges through fuel oil hedges. Such price fluctuations may cause the following: • an unrealized appreciation or depreciation of our contracted commitments to purchase or sell when purchase or sale prices under the commitments are compared with current commodity prices; • market values of natural gas inventories that differ from the cost of those commodities in inventory; and • actual cash outlays for the purchase of these commodities that differ from anticipated cash outlays. The derivatives that we use to hedge these risks are governed by our risk management policies for forward contracts, futures, options, and swaps. Our net positions are continually assessed within our structured hedging programs to determine whether new or offsetting transactions are required. The goal of the hedging program is generally to mitigate financial risks while ensuring that sufficient volumes are available to meet our requirements. Contracts we enter into as part of our risk management program may be settled financially, settled by physical delivery, or net settled with the counterparty. |
Share-based Compensation, Option and Incentive Plans Policy | Stock-based Compensation The following table summarizes Ameren's nonvested performance share unit and restricted stock unit activity for the three months ended March 31, 2019 : Performance Share Units Restricted Stock Units Share Units Weighted-average Fair Value per Share Unit Stock Units Weighted-average Fair Value per Stock Unit Nonvested at January 1, 2019 (a) 682,811 $ 56.58 155,253 $ 57.38 Granted 288,956 67.42 (b) 124,925 65.23 Forfeitures (2,228 ) 65.06 (833 ) 63.16 Vested and undistributed (c) (65,458 ) 62.04 (14,047 ) 61.77 Vested and distributed (176,923 ) 44.13 — — Nonvested at March 31, 2019 (d) 727,158 $ 63.40 265,298 $ 60.64 (a) Does not include 619,783 vested and undistributed performance share units and 26,557 vested and undistributed restricted stock units. (b) Significant inputs to the Monte Carlo simulation model used to calculate the fair value of performance share units granted include Ameren’s closing common share price of $65.23 at December 31, 2018 , Ameren’s common stock volatility of 17% , a volatility range for the peer group of 15% to 25% , and a three-year risk-free rate of 2.46% . (c) Vested and undistributed units are awards that vested due to attainment of retirement eligibility by certain employees, but have not yet been distributed. For vested and undistributed performance share units, the number of shares issued for retirement-eligible employees will vary depending on actual performance over the three -year performance period. (d) Does not include 333,466 vested and undistributed performance share units and 40,604 vested and undistributed restricted stock units. |
Deferred Compensation | Deferred Compensation As of March 31, 2019 , and December 31, 2018 , “Other deferred credits and liabilities” on Ameren’s balance sheet included deferred compensation obligations of $78 million and $80 million , respectively, recorded at the present value of future benefits to be paid. |
Revenue from Contract with Customer | Operating Revenues As of March 31, 2019 and 2018 , our remaining performance obligations for contracts with a term greater than one year were immaterial. The Ameren Companies elected not to disclose the aggregate amount of the transaction price allocated to the performance obligations that are unsatisfied as of the end of the reporting period for contracts with an initial expected term of one year or less. See Note 14 – Segment Information for disaggregated revenue information. |
Excise Taxes | Excise Taxes Ameren Missouri and Ameren Illinois collect from their customers excise taxes, including municipal and state excise taxes and gross receipts taxes, that are levied on the sale or distribution of natural gas and electricity. |
Short-Term Debt And Liquidity S
Short-Term Debt And Liquidity Short-Term Debt and Liquidity (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Debt Disclosure [Abstract] | |
Schedule of Short-term Debt | The following table presents commercial paper outstanding, net of issuance discounts, as of March 31, 2019 , and December 31, 2018 : March 31, 2019 December 31, 2018 Ameren (parent) $ 618 $ 470 Ameren Missouri 55 55 Ameren Illinois 126 72 Ameren consolidated $ 799 $ 597 The following table summarizes the borrowing activity and relevant interest rates under Ameren (parent)’s, Ameren Missouri’s, and Ameren Illinois’ commercial paper programs for the three months ended March 31, 2019 and 2018: Ameren (parent) Ameren Missouri Ameren Illinois Ameren Consolidated 2019 Average daily commercial paper outstanding at par value $ 480 $ 246 $ 89 $ 815 Weighted-average interest rate 2.87 % 2.84 % 2.76 % 2.85 % Peak commercial paper during period at par value (a) $ 618 $ 549 $ 130 $ 1,113 Peak interest rate 3.10 % 2.97 % 2.90 % 3.10 % 2018 Average daily commercial paper outstanding at par value $ 378 $ 213 $ 137 $ 728 Weighted-average interest rate 1.90 % 1.88 % 1.96 % 1.90 % Peak commercial paper during period at par value (a) $ 454 $ 282 $ 238 $ 960 Peak interest rate 2.35 % 2.40 % 2.55 % 2.55 % (a) The timing of peak outstanding commercial paper issuances varies by company. Therefore, the sum of individual company peak amounts may not equal the Ameren consolidated peak commercial paper issuances for the period. |
Other Income and Expenses (Tabl
Other Income and Expenses (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Other Nonoperating Income (Expense) [Abstract] | |
Other Income And Expenses | The following table presents the components of “Other Income, Net” in the Ameren Companies’ statements of income for the three months ended March 31, 2019 and 2018 : Three Months 2019 2018 Ameren: Three Months 2019 2018 Allowance for equity funds used during construction $ 6 $ 5 Interest income on industrial development revenue bonds 6 6 Other interest income 2 2 Non-service cost components of net periodic benefit income (a) 22 16 Miscellaneous income 2 1 Donations (6 ) (5 ) Miscellaneous expense (3 ) (2 ) Total Other Income, Net $ 29 $ 23 Ameren Missouri: Allowance for equity funds used during construction $ 4 $ 4 Interest income on industrial development revenue bonds 6 6 Non-service cost components of net periodic benefit income (a) 4 5 Miscellaneous income 1 1 Donations (2 ) (1 ) Miscellaneous expense (1 ) (2 ) Total Other Income, Net $ 12 $ 13 Ameren Illinois: Allowance for equity funds used during construction $ 2 $ 1 Interest income 2 2 Non-service cost components of net periodic benefit income 12 7 Miscellaneous income 1 — Donations (4 ) (4 ) Miscellaneous expense (2 ) — Total Other Income, Net $ 11 $ 6 (a) For the three months ended March 31, 2019 and 2018, the non-service cost components of net periodic benefit income were partially offset by a $7 million and $4 million deferral, respectively, due to a regulatory tracking mechanism for the difference between the level of such costs incurred by Ameren Missouri under GAAP and the level of such costs included in rates. |
Derivative Financial Instrume_2
Derivative Financial Instruments (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
Open Gross Derivative Volumes By Commodity Type | The following table presents open gross commodity contract volumes by commodity type for derivative assets and liabilities as of March 31, 2019 , and December 31, 2018 . As of March 31, 2019 , these contracts extended through October 2022, October 2023, and May 2032 for fuel oils, natural gas, and power, respectively. Quantity (in millions) 2019 2018 Commodity Ameren Missouri Ameren Illinois Ameren Ameren Missouri Ameren Illinois Ameren Fuel oils (in gallons) (a) 65 — 65 66 — 66 Natural gas (in mmbtu) 18 156 174 19 154 173 Power (in megawatthours) 2 8 10 1 8 9 (a) Consists of ultra-low-sulfur diesel products. |
Derivative Instruments Carrying Value | The following table presents the carrying value and balance sheet location of all derivative commodity contracts, none of which were designated as hedging instruments, as of March 31, 2019 , and December 31, 2018 : March 31, 2019 December 31, 2018 Balance Sheet Location Ameren Missouri Ameren Illinois Ameren Ameren Missouri Ameren Illinois Ameren Fuel oils Other current assets $ 5 $ — $ 5 $ 3 $ — $ 3 Other assets 4 — 4 5 — 5 Natural gas Other current assets — 3 3 — 1 1 Other assets — 3 3 — 2 2 Power Other current assets 1 — 1 4 — 4 Other assets 1 — 1 — — — Total assets $ 11 $ 6 $ 17 $ 12 $ 3 $ 15 Fuel oils Other current liabilities $ 3 $ — $ 3 $ 4 $ — $ 4 Other deferred credits and liabilities 4 — 4 9 — 9 Natural gas Other current liabilities 2 6 8 4 8 12 Other deferred credits and liabilities 1 4 5 1 6 7 Power Other current liabilities 2 14 16 4 14 18 Other deferred credits and liabilities — 170 170 — 169 169 Total liabilities $ 12 $ 194 $ 206 $ 22 $ 197 $ 219 |
Derivative Instruments With Credit Risk-Related Contingent Features | The following table presents, as of March 31, 2019 , the aggregate fair value of all derivative instruments with credit risk-related contingent features in a gross liability position, the cash collateral posted, and the aggregate amount of additional collateral that counterparties could require. The additional collateral required is the net liability position allowed under the master netting arrangements or similar agreements, assuming (1) the credit risk-related contingent features underlying these arrangements were triggered on March 31, 2019 , and (2) those counterparties with rights to do so requested collateral. Aggregate Fair Value of Derivative Liabilities (a) Cash Collateral Posted Potential Aggregate Amount of Additional Collateral Required (b) Ameren Missouri $ 64 $ 4 $ 58 Ameren Illinois 39 — 29 Ameren $ 103 $ 4 $ 87 (a) Before consideration of master netting arrangements or similar agreements and including NPNS and other accrual contract exposures. (b) As collateral requirements with certain counterparties are based on master netting arrangements or similar agreements, the aggregate amount of additional collateral required to be posted is determined after consideration of the effects of such arrangements. |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Fair Value Disclosures [Abstract] | |
Schedule Of Fair Value Hierarchy Of Assets And Liabilities Measured At Fair Value On Recurring Basis | The following table sets forth, by level within the fair value hierarchy, our assets and liabilities measured at fair value on a recurring basis as of March 31, 2019 , and December 31, 2018 : March 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Ameren Derivative assets – commodity contracts (a) : Fuel oils $ 2 $ — $ 7 $ 9 $ 1 $ — $ 7 $ 8 Natural gas — 3 3 6 — 2 1 3 Power — — 2 2 — 1 3 4 Total derivative assets – commodity contracts $ 2 $ 3 $ 12 $ 17 $ 1 $ 3 $ 11 $ 15 Nuclear decommissioning trust fund: Equity securities: U.S. large capitalization $ 488 $ — $ — $ 488 $ 427 $ — $ — $ 427 Debt securities: U.S. Treasury and agency securities — 151 — 151 — 148 — 148 Corporate bonds — 76 — 76 — 72 — 72 Other — 33 — 33 — 32 — 32 Total nuclear decommissioning trust fund $ 488 $ 260 $ — $ 748 (b) $ 427 $ 252 $ — $ 679 (b) Total Ameren $ 490 $ 263 $ 12 $ 765 $ 428 $ 255 $ 11 $ 694 Ameren Missouri Derivative assets – commodity contracts (a) : Fuel oils $ 2 $ — $ 7 $ 9 $ 1 $ — $ 7 $ 8 Power — — 2 2 — 1 3 4 Total derivative assets – commodity contracts $ 2 $ — $ 9 $ 11 $ 1 $ 1 $ 10 $ 12 Nuclear decommissioning trust fund: Equity securities: U.S. large capitalization $ 488 $ — $ — $ 488 $ 427 $ — $ — $ 427 Debt securities: U.S. Treasury and agency securities — 151 — 151 — 148 — 148 Corporate bonds — 76 — 76 — 72 — 72 Other — 33 — 33 — 32 — 32 Total nuclear decommissioning trust fund $ 488 $ 260 $ — $ 748 (b) $ 427 $ 252 $ — $ 679 (b) Total Ameren Missouri $ 490 $ 260 $ 9 $ 759 $ 428 $ 253 $ 10 $ 691 Ameren Illinois Derivative assets – commodity contracts (a) : Natural gas $ — $ 3 $ 3 $ 6 $ — $ 2 $ 1 $ 3 Liabilities: Ameren Derivative liabilities – commodity contracts (a) : Fuel oils $ 1 $ — $ 6 $ 7 $ 2 $ — $ 11 $ 13 Natural gas — 10 3 13 — 15 4 19 Power — — 186 186 — 1 186 187 Total Ameren $ 1 $ 10 $ 195 $ 206 $ 2 $ 16 $ 201 $ 219 Ameren Missouri Derivative liabilities – commodity contracts (a) : Fuel oils $ 1 $ — $ 6 $ 7 $ 2 $ — $ 11 $ 13 Natural gas — 3 — 3 — 5 — 5 Power — — 2 2 — 1 3 4 Total Ameren Missouri $ 1 $ 3 $ 8 $ 12 $ 2 $ 6 $ 14 $ 22 Ameren Illinois Derivative liabilities – commodity contracts (a) : Natural gas $ — $ 7 $ 3 $ 10 $ — $ 10 $ 4 $ 14 Power — — 184 184 — — 183 183 Total Ameren Illinois $ — $ 7 $ 187 $ 194 $ — $ 10 $ 187 $ 197 (a) The derivative asset and liability balances are presented net of registrant and counterparty credit considerations. (b) Balance excludes $6 million and $5 million of cash and cash equivalents, receivables, payables, and accrued income, net, for March 31, 2019 , and December 31, 2018 , respectively. |
Schedule Of Changes In The Fair Value Of Financial Assets And Liabilities Classified As Level Three In The Fair Value Hierarchy | The following table presents the fair value reconciliation of Level 3 power derivative contract assets and liabilities measured at fair value on a recurring basis for the three months ended March 31, 2019 and 2018 : 2019 2018 Ameren Missouri Ameren Illinois Ameren Ameren Missouri Ameren Illinois Ameren Beginning balance at January 1 $ — $ (183 ) $ (183 ) $ 7 $ (195 ) $ (188 ) Realized and unrealized losses included in regulatory assets/liabilities — (4 ) (4 ) (2 ) 1 (1 ) Settlements — 3 3 (1 ) 3 2 Ending balance at March 31 $ — $ (184 ) $ (184 ) $ 4 $ (191 ) $ (187 ) Change in unrealized losses related to assets/liabilities held at March 31 $ — $ (4 ) $ (4 ) $ (1 ) $ 1 $ — |
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques | The following table describes the valuation techniques and significant unobservable inputs utilized for the fair value of our Level 3 power derivative contract assets and liabilities as of March 31, 2019 , and December 31, 2018 : Fair Value (a) Weighted Average Commodity Assets Liabilities Valuation Technique(s) Unobservable Input Range 2019 Power (b) $ 2 $ (186) Discounted cash flow Average forward peak and off-peak pricing – forwards/swaps ($/MWh) (c) 24 – 38 28 Nodal basis ($/MWh) (c) (9) – 0 (2) Fundamental energy production model Estimated future natural gas prices ($/mmbtu) (c) 3 – 4 3 2018 Power (b) $ 3 $ (186) Discounted cash flow Average forward peak and off-peak pricing – forwards/swaps ($/MWh) (c) 23 – 39 28 Nodal basis ($/MWh) (c) (9) – 0 (2) Fundamental energy production model Estimated future natural gas prices ($/mmbtu) (c) 3 – 4 3 (a) The derivative asset and liability balances are presented net of registrant and counterparty credit considerations. (b) Power valuations use visible third-party pricing evaluated by month for peak and off-peak demand through 2022. Valuations beyond 2022 use fundamentally modeled pricing by month for peak and off-peak demand. (c) Generally, significant increases (decreases) in this input in isolation would result in a significantly higher (lower) fair value measurement. |
Schedule of Financial Assets and Liabilities | The following table sets forth, by level within the fair value hierarchy, the carrying amount and fair value of financial assets and liabilities disclosed, but not carried, at fair value as of March 31, 2019 , and December 31, 2018 : March 31, 2019 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total Ameren: Cash, cash equivalents, and restricted cash $ 118 $ 118 $ — $ — $ 118 Investments in held-to-maturity debt securities (a) 270 — 270 — 270 Short-term debt 799 — 799 — 799 Long-term debt (including current portion) (a) 8,557 (b) — 8,623 447 (c) 9,070 Ameren Missouri: Cash, cash equivalents, and restricted cash $ 12 $ 12 $ — $ — $ 12 Investments in held-to-maturity debt securities (a) 270 — 270 — 270 Short-term debt 55 — 55 — 55 Long-term debt (including current portion) (a) 4,116 (b) — 4,404 — 4,404 Ameren Illinois: Cash, cash equivalents, and restricted cash $ 93 $ 93 $ — $ — $ 93 Short-term debt 126 — 126 — 126 Long-term debt (including current portion) 3,296 (b) — 3,515 — 3,515 December 31, 2018 Ameren: Cash, cash equivalents, and restricted cash $ 107 $ 107 $ — $ — $ 107 Investments in held-to-maturity debt securities (a) 270 — 270 — 270 Short-term debt 597 — 597 — 597 Long-term debt (including current portion) (a) 8,439 (b) — 8,240 429 (c) 8,669 Ameren Missouri: Cash, cash equivalents, and restricted cash $ 8 $ 8 $ — $ — $ 8 Investments in held-to-maturity debt securities (a) 270 — 270 — 270 Short-term debt 55 — 55 — 55 Long-term debt (including current portion) (a) 3,998 (b) — 4,156 — 4,156 Ameren Illinois: Cash, cash equivalents, and restricted cash $ 80 $ 80 $ — $ — $ 80 Short-term debt 72 — 72 — 72 Long-term debt (including current portion) 3,296 (b) — 3,391 — 3,391 (a) Ameren and Ameren Missouri have investments in industrial development revenue bonds, classified as held-to-maturity and recorded in “Other Assets,” that are equal to the finance obligations for the Peno Creek and Audrain CT energy centers. As of March 31, 2019 , and December 31, 2018 , the carrying amount of both the investments in industrial development revenue bonds and the finance obligations approximated fair value. (b) Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $62 million , $25 million , and $32 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of March 31, 2019 . Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $58 million , $22 million , and $31 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of December 31, 2018 . (c) The Level 3 fair value amount consists of ATXI’s senior unsecured notes. |
Related Party Transactions (Tab
Related Party Transactions (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Related Party Transactions [Abstract] | |
Schedule of Related Party Transactions | The following table presents the impact on Ameren Missouri and Ameren Illinois of related-party transactions for the three months ended March 31, 2019 and 2018 : Three Months Agreement Income Statement Line Item Ameren Missouri Ameren Illinois Ameren Missouri power supply Operating Revenues 2019 $ (b) $ (a) agreements with Ameren Illinois 2018 3 (a) Ameren Missouri and Ameren Illinois Operating Revenues 2019 7 1 rent and facility services 2018 5 1 Ameren Missouri and Ameren Illinois Operating Revenues 2019 (b) (b) miscellaneous support services 2018 (b) (b) Total Operating Revenues 2019 $ 7 $ 1 2018 8 1 Ameren Illinois power supply Purchased Power 2019 $ (a) $ (b) agreements with Ameren Missouri 2018 (a) 3 Ameren Illinois transmission Purchased Power 2019 (a) (b) services with ATXI 2018 (a) (b) Total Purchased Power 2019 $ (a) $ (b) 2018 (a) 3 Ameren Missouri and Ameren Illinois Other Operations and Maintenance 2019 $ (b) $ 1 rent and facility services 2018 (b) 2 Ameren Services support services Other Operations and Maintenance 2019 32 30 agreement 2018 33 30 Total Other Operations and Maintenance 2019 $ 32 $ 31 2018 33 32 Money pool borrowings (advances) Interest Charges/ Other Income, Net 2019 $ — $ — 2018 (b) (b) (a) Not applicable. (b) Amount less than $1 million. |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Commitments and Contingencies Disclosure [Abstract] | |
Long-term Purchase Commitment | The table below presents our estimated minimum fuel, purchased power, and other commitments at March 31, 2019 . Ameren’s and Ameren Illinois’ purchased power commitments include the Ameren Illinois agreements entered into as part of the IPA-administered power procurement process. Included in the Other column are minimum purchase commitments under contracts for equipment, design and construction, and meter reading services, among other agreements, at March 31, 2019 . Coal Natural Gas (a) Nuclear Fuel Purchased Power (b)(c) Methane Gas Other Total Ameren: 2019 $ 279 $ 154 $ 25 $ 88 (d) $ 2 $ 52 $ 600 2020 160 158 43 54 3 42 460 2021 121 85 58 10 3 30 307 2022 72 32 13 — 3 26 146 2023 — 8 41 — 3 29 81 Thereafter — 34 29 — 27 71 161 Total $ 632 $ 471 $ 209 $ 152 $ 41 $ 250 $ 1,755 Ameren Missouri: 2019 $ 279 $ 33 $ 25 $ — $ 2 $ 39 $ 378 2020 160 34 43 — 3 29 269 2021 121 16 58 — 3 25 223 2022 72 5 13 — 3 26 119 2023 — 5 41 — 3 29 78 Thereafter — 13 29 — 27 55 124 Total $ 632 $ 106 $ 209 $ — $ 41 $ 203 $ 1,191 Ameren Illinois: 2019 $ — $ 121 $ — $ 88 (d) $ — $ 5 $ 214 2020 — 124 — 54 — 4 182 2021 — 69 — 10 — — 79 2022 — 27 — — — — 27 2023 — 3 — — — — 3 Thereafter — 21 — — — — 21 Total $ — $ 365 $ — $ 152 $ — $ 9 $ 526 (a) Includes amounts for generation and for distribution. (b) The purchased power amounts for Ameren and Ameren Illinois exclude agreements for renewable energy credits through 2034 with various renewable energy suppliers due to the contingent nature of the payment amounts. (c) The purchased power amounts for Ameren and Ameren Missouri exclude a 102 -megawatt power purchase agreement with a wind farm operator, which expires in 2024, due to the contingent nature of the payment amounts. (d) In January 2018, as required by the FEJA, Ameren Illinois entered into 10-year agreements to acquire zero emission credits. Annual zero emission credit commitment amounts will be published by the IPA each May prior to the start of the subsequent planning year. The amounts above reflect Ameren Illinois’ commitment to acquire approximately $10 million of zero emission credits through May 2019. |
Callaway Energy Center (Tables)
Callaway Energy Center (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Nuclear Waste Matters [Abstract] | |
Schedule of Insurance Coverage at Callaway Energy Center | The following table presents insurance coverage at Ameren Missouri’s Callaway energy center as of April 1, 2019. The property coverage and the nuclear liability coverage renewal dates are April 1 and January 1, respectively, of each year. Both coverages were renewed in 2019. Type and Source of Coverage Maximum Coverages Maximum Assessments for Single Incidents Public liability and nuclear worker liability: American Nuclear Insurers $ 450 $ — Pool participation 13,623 (a) 138 (b) $ 14,073 (c) $ 138 Property damage: NEIL and EMANI $ 3,200 (d) $ 28 (e) Replacement power: NEIL $ 490 (f) $ 7 (e) (a) Provided through mandatory participation in an industrywide retrospective premium assessment program. The maximum coverage available is dependent on the number of United States commercial reactors participating in the program. (b) Retrospective premium under the Price-Anderson Act. This is subject to retrospective assessment with respect to a covered loss in excess of $450 million in the event of an incident at any licensed United States commercial reactor, payable at $21 million per year. (c) Limit of liability for each incident under the Price-Anderson liability provisions of the Atomic Energy Act of 1954, as amended. This limit is subject to change to account for the effects of inflation and changes in the number of licensed reactors. (d) NEIL provides $2.7 billion in property damage, stabilization, decontamination, and premature decommissioning insurance for radiation events and $2.3 billion in property damage insurance for nonradiation events. EMANI provides $490 million in property damage insurance for both radiation and nonradiation events. (e) All NEIL insured plants could be subject to assessments should losses exceed the accumulated funds from NEIL. (f) Provides replacement power cost insurance in the event of a prolonged accidental outage. Weekly indemnity up to $4.5 million for 52 weeks, which commences after the first twelve weeks of an outage, plus up to $3.6 million per week for a minimum of 71 weeks thereafter for a total not exceeding the policy limit of $490 million . Nonradiation events are limited to $328 million . |
Retirement Benefits (Tables)
Retirement Benefits (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Defined Benefit Plan [Abstract] | |
Components Of Net Periodic Benefit Cost | The following table presents the components of the net periodic benefit cost (income) incurred for Ameren’s pension and postretirement benefit plans for the three months ended March 31, 2019 and 2018 : Pension Benefits Postretirement Benefits Three Months Three Months 2019 2018 2019 2018 Service cost (a) $ 22 $ 25 $ 4 $ 5 Non-service cost components: Interest cost 47 42 11 11 Expected return on plan assets (69 ) (69 ) (19 ) (19 ) Amortization of: Prior service benefit — — (1 ) (1 ) Actuarial loss (gain) 6 16 (4 ) — Total non-service cost components (b) $ (16 ) $ (11 ) $ (13 ) $ (9 ) Net periodic benefit cost (income) $ 6 $ 14 $ (9 ) $ (4 ) (a) Service cost, net of capitalization, is reflected in “Operating Expenses – Other operations and maintenance” on Ameren’s statement of income. (b) Non-service cost components are reflected in “Other Income, Net” on Ameren’s statement of income. See Note 5 – Other Income, Net for additional information. |
Summary Of Benefit Plan Costs Incurred | Ameren Missouri and Ameren Illinois are responsible for their respective shares of Ameren’s pension and postretirement costs. The following table presents the respective share of net periodic pension and other postretirement benefit costs (income) incurred for the three months ended March 31, 2019 and 2018 : Pension Benefits Postretirement Benefits Three Months Three Months 2019 2018 2019 2018 Ameren Missouri (a) $ 1 $ 5 $ (2 ) $ — Ameren Illinois 5 9 (7 ) (4 ) Ameren (a) $ 6 $ 14 $ (9 ) $ (4 ) (a) Does not include the impact of the regulatory tracking mechanism for the difference between the level of pension and postretirement benefit costs incurred by Ameren Missouri under GAAP and the level of such costs included in rates. |
Income Taxes Income Taxes (Tabl
Income Taxes Income Taxes (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Income Tax Disclosure [Abstract] | |
Schedule of Effective Income Tax Rate Reconciliation | The following table presents a reconciliation of the federal statutory corporate income tax rate to the effective income tax rate for the three months ended March 31, 2019 and 2018 : Ameren Ameren Missouri Ameren Illinois Three Months 2019 2018 2019 2018 2019 2018 Federal statutory corporate income tax rate: 21% 21% 21% 21% 21% 21% Increases (decreases) from: Amortization of excess deferred taxes (7) (2) (a) (12) — (a) (3) (3) Other depreciation differences — — — 1 — — Amortization of deferred investment tax credit (1) (1) (1) (1) — — State tax 6 7 4 4 7 7 Stock-based compensation (7) (3) — — — — Other — — (3) — — — Effective income tax rate 12% 22% 9% 25% 25% 25% |
Supplemental Information (Table
Supplemental Information (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Supplemental Information [Abstract] | |
Schedule of Cash and Cash Equivalents Including Restricted Cash | The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets and the statements of cash flows as of March 31, 2019 , and December 31, 2018 : March 31, 2019 December 31, 2018 Ameren Ameren Ameren Ameren Ameren Ameren Cash and cash equivalents $ 8 $ — $ — $ 16 $ — $ — Restricted cash included in “Other current assets” 16 5 6 13 4 6 Restricted cash included in “Other assets” 87 — 87 74 — 74 Restricted cash included in “Nuclear decommissioning trust fund” 7 7 — 4 4 — Total cash, cash equivalents, and restricted cash $ 118 $ 12 $ 93 $ 107 $ 8 $ 80 |
Lease Supplemental Information | The following table provides supplemental balance sheet information related to operating leases as of March 31, 2019 : Ameren Ameren Missouri Other assets $ 36 $ 34 Other current liabilities 7 6 Other deferred credits and liabilities 29 28 Weighted average remaining operating lease term 6 years 6 years Weighted average discount rate (a) 3.6 % 3.6 % (a) As most of our lease agreements do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. We use the implicit rate when readily determinable. |
Schedule of Maturity of Operating Lease Liabilities | The following table presents Ameren’s and Ameren Missouri’s remaining maturities of operating lease liabilities as of March 31, 2019 : Ameren Ameren Missouri 2019 $ 6 $ 5 2020 7 7 2021 7 6 2022 6 5 2023 5 5 Thereafter 10 10 Total lease payments 41 38 Less imputed interest 5 4 Total (a) $ 36 $ 34 (a) The amount of remaining maturities of operating lease liabilities under previous authoritative accounting guidance as of December 31, 2018, is materially consistent to the amount as of March 31, 2019. Maturities of certain financing arrangements, including the Peno Creek and Audrain energy centers' long-term agreements, are no longer required to be disclosed as lease-related maturities. See Note 5 - Long-Term Debt and Equity Financings under Part II, Item 8, in the Form 10-K for further information on financing arrangements. |
Schedule of Cash Flow, Supplemental Disclosures | Supplemental Cash Flow Information The following table provides noncash investing activity excluded from the statements of cash flows for the three months ended March 31, 2019 and 2018 : March 31, 2019 March 31, 2018 Ameren Ameren Missouri Ameren Illinois Ameren Ameren Missouri Ameren Illinois Accrued capital expenditures $ 208 $ 92 $ 106 $ 202 $ 73 $ 114 Net realized and unrealized gain (loss) – nuclear decommissioning trust fund 64 64 — (11 ) (11 ) — |
Asset Retirement Obligation Disclosure | The following table provides a reconciliation of the beginning and ending carrying amount of AROs for the three months ended March 31, 2019 : Ameren Missouri Ameren Illinois (a) Ameren Balance at December 31, 2018 $ 646 (a) $ 4 (b) $ 650 (a) Liabilities settled (3 ) — (3 ) Accretion 6 (c) — 6 (c) Balance at March 31, 2019 $ 649 (a) $ 4 (b) $ 653 (a) (a) Balance included $23 million in “Other current liabilities” on the balance sheet as of both December 31, 2018 , and March 31, 2019 . (b) Included in “Other deferred credits and liabilities” on the balance sheet. (c) Accretion expense attributable to Ameren Missouri was recorded as a decrease to regulatory liabilities. |
Summary Of Nonvested Shares Related To Long-Term Incentive Plan | The following table summarizes Ameren's nonvested performance share unit and restricted stock unit activity for the three months ended March 31, 2019 : Performance Share Units Restricted Stock Units Share Units Weighted-average Fair Value per Share Unit Stock Units Weighted-average Fair Value per Stock Unit Nonvested at January 1, 2019 (a) 682,811 $ 56.58 155,253 $ 57.38 Granted 288,956 67.42 (b) 124,925 65.23 Forfeitures (2,228 ) 65.06 (833 ) 63.16 Vested and undistributed (c) (65,458 ) 62.04 (14,047 ) 61.77 Vested and distributed (176,923 ) 44.13 — — Nonvested at March 31, 2019 (d) 727,158 $ 63.40 265,298 $ 60.64 (a) Does not include 619,783 vested and undistributed performance share units and 26,557 vested and undistributed restricted stock units. (b) Significant inputs to the Monte Carlo simulation model used to calculate the fair value of performance share units granted include Ameren’s closing common share price of $65.23 at December 31, 2018 , Ameren’s common stock volatility of 17% , a volatility range for the peer group of 15% to 25% , and a three-year risk-free rate of 2.46% . (c) Vested and undistributed units are awards that vested due to attainment of retirement eligibility by certain employees, but have not yet been distributed. For vested and undistributed performance share units, the number of shares issued for retirement-eligible employees will vary depending on actual performance over the three -year performance period. (d) Does not include 333,466 vested and undistributed performance share units and 40,604 vested and undistributed restricted stock units. |
Schedule of excise taxes | The following table presents the excise taxes recorded on a gross basis in “Operating Revenues – Electric,” “Operating Revenues – Natural gas” and “Operating Expenses – Taxes other than income taxes” on the statements of income for the three months ended March 31, 2019 and 2018 : Three Months 2019 2018 Ameren Missouri $ 31 $ 34 Ameren Illinois 39 35 (a) Ameren $ 70 $ 69 (a) (a) Amounts have been adjusted from those previously reported to reflect additional excise taxes for the three months ended March 31, 2018. |
Segment Information (Tables)
Segment Information (Tables) | 3 Months Ended |
Mar. 31, 2019 | |
Segment Reporting [Abstract] | |
Schedule Of Segment Reporting Information By Segment | The following tables present revenues, net income attributable to common shareholders, and capital expenditures by segment at Ameren and Ameren Illinois for the three months ended March 31, 2019 and 2018 . Ameren, Ameren Missouri, and Ameren Illinois management review segment capital expenditure information rather than any individual or total asset amount. Ameren Three Months Ameren Missouri Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Transmission Other Intersegment Eliminations Ameren 2019 External revenues $ 751 $ 386 $ 320 $ 99 $ — $ — $ 1,556 Intersegment revenues 7 1 — 15 — (23 ) — Net income attributable to Ameren common shareholders 39 36 57 44 (a) 15 — 191 Capital expenditures 240 124 51 121 10 (2 ) 544 2018 External revenues $ 784 $ 399 $ 311 $ 91 $ — $ — $ 1,585 Intersegment revenues 8 1 — 13 — (22 ) — Net income attributable to Ameren common shareholders 38 33 42 37 (a) 1 — 151 Capital expenditures 249 122 60 145 7 (4 ) 579 (a) Ameren Transmission earnings include an allocation of financing costs from Ameren (parent). Ameren Illinois Three Months Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Illinois Transmission Intersegment Eliminations Ameren Illinois 2019 External revenues $ 387 $ 320 $ 55 $ — $ 762 Intersegment revenues — — 15 (15 ) — Net income available to common shareholder 36 57 27 — 120 Capital expenditures 124 51 92 — 267 2018 External revenues $ 400 $ 311 $ 49 $ — $ 760 Intersegment revenues — — 13 (13 ) — Net income available to common shareholder 33 42 20 — 95 Capital expenditures 122 60 118 — 300 |
Disaggregation of Revenue | The following tables present disaggregated revenues by segment at Ameren and Ameren Illinois for the three months ended March 31, 2019 and 2018 . Economic factors affect the nature, timing, amount, and uncertainty of revenues and cash flows in a similar manner across customer classes. Revenues from alternative revenue programs have a similar distribution among customer classes as revenues from contracts with customers. Other revenues not associated with contracts with customers are presented in the Other customer classification, along with electric transmission and off-system revenues. Ameren Three Months Ameren Missouri Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Transmission Other Intersegment Eliminations Ameren 2019 Residential $ 312 $ 217 $ — $ — $ — $ — $ 529 Commercial 239 123 — — — — 362 Industrial 55 34 — — — — 89 Other 98 13 — 114 — (23 ) 202 Total electric revenues $ 704 $ 387 $ — $ 114 $ — $ (23 ) $ 1,182 Residential $ 38 $ — $ 246 $ — $ — $ — $ 284 Commercial 16 — 65 — — — 81 Industrial 2 — 4 — — — 6 Other (2 ) — 5 — — — 3 Total gas revenues $ 54 $ — $ 320 $ — $ — $ — $ 374 Total revenues (a) $ 758 $ 387 $ 320 $ 114 $ — $ (23 ) $ 1,556 2018 Residential $ 332 $ 219 $ — $ — $ — $ — $ 551 Commercial 252 124 — — — — 376 Industrial 61 35 — — — — 96 Other 96 22 — 104 — (22 ) 200 Total electric revenues $ 741 $ 400 $ — $ 104 $ — $ (22 ) $ 1,223 Residential $ 41 $ — $ 243 $ — $ — $ — $ 284 Commercial 16 — 67 — — — 83 Industrial 2 — 6 — — — 8 Other (8 ) — (5 ) — — — (13 ) Total gas revenues $ 51 $ — $ 311 $ — $ — $ — $ 362 Total revenues (a) $ 792 $ 400 $ 311 $ 104 $ — $ (22 ) $ 1,585 (a) The following table presents increases/(decreases) in revenues from alternative revenue programs and other revenues not from contracts with customers for the three months ended March 31, 2019 and 2018 : Three Months Ameren Missouri Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Transmission Ameren 2019 Revenues from alternative revenue programs $ 15 $ 22 $ (3 ) $ (5 ) $ 29 Other revenues not from contracts with customers 5 3 1 — 9 2018 Revenues from alternative revenue programs $ (4 ) $ 31 $ (3 ) $ (4 ) $ 20 Other revenues not from contracts with customers 14 10 1 — 25 Ameren Illinois Three Months Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Illinois Transmission Intersegment Eliminations Total Ameren Illinois 2019 Residential $ 217 $ 246 $ — $ — $ 463 Commercial 123 65 — — 188 Industrial 34 4 — — 38 Other 13 5 70 (15 ) 73 Total revenues (a) $ 387 $ 320 $ 70 $ (15 ) $ 762 2018 Residential $ 219 $ 243 $ — $ — $ 462 Commercial 124 67 — — 191 Industrial 35 6 — — 41 Other 22 (5 ) 62 (13 ) 66 Total revenues (a) $ 400 $ 311 $ 62 $ (13 ) $ 760 (a) The following table presents increases/(decreases) in revenues from alternative revenue programs and other revenues not from contracts with customers for the Ameren Illinois segments for the three months ended March 31, 2019 and 2018 : Three Months Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Illinois Transmission Ameren Illinois 2019 Revenues from alternative revenue programs $ 22 $ (3 ) $ (5 ) $ 14 Other revenues not from contracts with customers 3 1 — 4 2018 Revenues from alternative revenue programs $ 31 $ (3 ) $ (4 ) $ 24 Other revenues not from contracts with customers 10 1 — 11 |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018 |
Basis Of Presentation And Significant Accounting Policies [Line Items] | ||
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net | $ 23 | $ 22 |
Cash Surrender Value of Life Insurance | 258 | 244 |
Corporate owned life insurance, borrowings | 113 | 113 |
Unrecorded Unconditional Purchase Obligation | 1,755 | |
Ameren Illinois Company | ||
Basis Of Presentation And Significant Accounting Policies [Line Items] | ||
Cash Surrender Value of Life Insurance | 123 | 122 |
Corporate owned life insurance, borrowings | 113 | $ 113 |
Unrecorded Unconditional Purchase Obligation | 526 | |
Variable Interest Entity, Not Primary Beneficiary [Member] | ||
Basis Of Presentation And Significant Accounting Policies [Line Items] | ||
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount | 16 | |
Partnership Funding Commitment | ||
Basis Of Presentation And Significant Accounting Policies [Line Items] | ||
Unrecorded Unconditional Purchase Obligation | $ 15 |
Rate And Regulatory Matters (Na
Rate And Regulatory Matters (Narrative-Missouri) (Detail) $ in Millions | 3 Months Ended | ||||
Jun. 30, 2019USD ($)MWh | Mar. 31, 2019USD ($) | Dec. 31, 2018MWh | Jun. 30, 2018MWh | Mar. 31, 2018USD ($) | |
Rate And Regulatory Matters [Line Items] | |||||
Total operating revenues | $ 1,556 | $ 1,585 | |||
Union Electric Company | |||||
Rate And Regulatory Matters [Line Items] | |||||
Depreciation Percentage Not Included in PISA Deferral | 15.00% | ||||
Wind Generation Facility | Union Electric Company | |||||
Rate And Regulatory Matters [Line Items] | |||||
Amount of Megawatts | MWh | 157 | 400 | |||
Estimated Capital Project Costs | $ 1,400 | ||||
Final Rate Order | Natural Gas | Union Electric Company | |||||
Rate And Regulatory Matters [Line Items] | |||||
Public Utilities, Interim Rate Increase (Decrease), Amount | 2 | ||||
Pending Rate Case [Member] | Natural Gas | Union Electric Company | |||||
Rate And Regulatory Matters [Line Items] | |||||
Public Utilities, Requested Rate Increase (Decrease), Amount | $ 4 | ||||
Public Utilities, Requested Return on Equity, Percentage | 10.30% | ||||
Public Utilities, Requested Equity Capital Structure, Percentage | 51.84% | ||||
Rate Base | $ 259 | ||||
Public Utilities, Requested Rate Increase (Decrease) on Interim Rates, Amount | 6 | ||||
MEEIA 2013 & 2016 [Domain] | Final Rate Order | Electricity | Union Electric Company | |||||
Rate And Regulatory Matters [Line Items] | |||||
Total operating revenues | $ 20 | ||||
MEEIA 2016 | Final Rate Order | Electricity | Union Electric Company | |||||
Rate And Regulatory Matters [Line Items] | |||||
Total operating revenues | $ 5 | ||||
Subsequent Event | Wind Generation Facility | Union Electric Company | |||||
Rate And Regulatory Matters [Line Items] | |||||
Amount of Megawatts | MWh | 300 | ||||
Subsequent Event | Pending Rate Case [Member] | Natural Gas | Union Electric Company | |||||
Rate And Regulatory Matters [Line Items] | |||||
Public Utilities, Requested Rate Increase (Decrease), Amount | $ 1 | ||||
Public Utilities, Requested Return on Equity, Percentage | 9.50% | ||||
Public Utilities, Requested Equity Capital Structure, Percentage | 50.00% |
Rate And Regulatory Matters (_2
Rate And Regulatory Matters (Narrative-Illinois) (Detail) - USD ($) $ in Millions | 3 Months Ended | ||
Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | |
Rate And Regulatory Matters [Line Items] | |||
Regulatory Assets, Noncurrent | $ 1,134 | $ 1,127 | |
Ameren Illinois Company | |||
Rate And Regulatory Matters [Line Items] | |||
Regulatory Assets, Noncurrent | 776 | $ 759 | |
Ameren Transmission Company of Illinois | |||
Rate And Regulatory Matters [Line Items] | |||
Estimated Capital Project Costs | 81 | ||
Property, Plant and Equipment, Additions | 38 | ||
2019 IEIMA Revenue Requirement Reconciliation | IEIMA | Ameren Illinois Company | Electric Distribution | |||
Rate And Regulatory Matters [Line Items] | |||
Regulatory Assets, Noncurrent | $ 41 | ||
Subsequent Event | Pending Rate Case [Member] | IEIMA | Ameren Illinois Company | Electric Distribution | |||
Rate And Regulatory Matters [Line Items] | |||
Public Utilities, Requested Rate Increase (Decrease), Amount | $ 7 |
Rate And Regulatory Matters (_3
Rate And Regulatory Matters (Narrative-Federal) (Detail) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Dec. 31, 2018 | |
Rate And Regulatory Matters [Line Items] | ||
Current regulatory liabilities | $ 161 | $ 149 |
Ameren Illinois Company | ||
Rate And Regulatory Matters [Line Items] | ||
Current regulatory liabilities | $ 79 | $ 62 |
Midwest Independent Transmission System Operator, Inc | ||
Rate And Regulatory Matters [Line Items] | ||
Public Utilities, Requested Return on Equity, Percentage | 12.38% | |
Midwest Independent Transmission System Operator, Inc | Final Rate Order | ||
Rate And Regulatory Matters [Line Items] | ||
Public Utilities, Requested Return on Equity, Percentage | 10.32% | |
Customer Requested Rate on Equity | 9.15% | |
Incentive adder to FERC allowed base return on common equity | 0.50% | |
Midwest Independent Transmission System Operator, Inc | Administrative Law Judge | ||
Rate And Regulatory Matters [Line Items] | ||
Public Utilities, Requested Return on Equity, Percentage | 9.70% | |
Midwest Independent Transmission System Operator, Inc | Pending Ferc Case | ||
Rate And Regulatory Matters [Line Items] | ||
Current regulatory liabilities | $ 44 | |
Midwest Independent Transmission System Operator, Inc | Pending Ferc Case | Ameren Illinois Company | ||
Rate And Regulatory Matters [Line Items] | ||
Current regulatory liabilities | $ 26 | |
Maximum | Midwest Independent Transmission System Operator, Inc | Final Rate Order | ||
Rate And Regulatory Matters [Line Items] | ||
Public Utilities, Requested Return on Equity, Percentage | 10.82% | |
Maximum | Midwest Independent Transmission System Operator, Inc | Administrative Law Judge | ||
Rate And Regulatory Matters [Line Items] | ||
Public Utilities, Requested Return on Equity, Percentage | 10.20% |
Short-Term Debt And Liquidity (
Short-Term Debt And Liquidity (Narrative) (Detail) | 3 Months Ended | |
Mar. 31, 2019USD ($) | Mar. 31, 2018 | |
Credit Agreements | ||
Short-term Debt [Line Items] | ||
Line of credit facility, maximum borrowing capacity | $ 1,292,000,000 | |
Actual debt-to-capital ratio | 0.54 | |
Utilities | ||
Short-term Debt [Line Items] | ||
Short-term Debt, Weighted Average Interest Rate, over Time | 2.87% | 1.90% |
Union Electric Company | Missouri Credit Agreement | ||
Short-term Debt [Line Items] | ||
Actual debt-to-capital ratio | 0.48 | |
Ameren Illinois Company | Illinois Credit Agreement | ||
Short-term Debt [Line Items] | ||
Actual debt-to-capital ratio | 0.47 |
Short-Term Debt and Liquidity_2
Short-Term Debt and Liquidity (Commercial Paper outstanding) (Details) - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018 |
Short-term Debt [Line Items] | ||
Commercial paper outstanding | $ 799 | $ 597 |
Ameren (parent) | ||
Short-term Debt [Line Items] | ||
Commercial paper outstanding | 618 | 470 |
Union Electric Company | ||
Short-term Debt [Line Items] | ||
Commercial paper outstanding | 55 | 55 |
Ameren Illinois Company | ||
Short-term Debt [Line Items] | ||
Commercial paper outstanding | $ 126 | $ 72 |
Short-Term Debt and Liquidity_3
Short-Term Debt and Liquidity (Commercial Paper) (Details) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Short-term Debt [Line Items] | ||
Short-term Debt, Average Outstanding Amount | $ 815 | $ 728 |
Weighted-average interest rate | 2.85% | 1.90% |
Short-term Debt, Maximum Amount Outstanding During Period | $ 1,113 | $ 960 |
Peak interest rate | 3.10% | 2.55% |
Ameren (parent) | ||
Short-term Debt [Line Items] | ||
Short-term Debt, Average Outstanding Amount | $ 480 | $ 378 |
Weighted-average interest rate | 2.87% | 1.90% |
Short-term Debt, Maximum Amount Outstanding During Period | $ 618 | $ 454 |
Peak interest rate | 3.10% | 2.35% |
Union Electric Company | ||
Short-term Debt [Line Items] | ||
Short-term Debt, Average Outstanding Amount | $ 246 | $ 213 |
Weighted-average interest rate | 2.84% | 1.88% |
Short-term Debt, Maximum Amount Outstanding During Period | $ 549 | $ 282 |
Peak interest rate | 2.97% | 2.40% |
Ameren Illinois Company | ||
Short-term Debt [Line Items] | ||
Short-term Debt, Average Outstanding Amount | $ 89 | $ 137 |
Weighted-average interest rate | 2.76% | 1.96% |
Short-term Debt, Maximum Amount Outstanding During Period | $ 130 | $ 238 |
Peak interest rate | 2.90% | 2.55% |
Long-Term debt and Equity Fin_2
Long-Term debt and Equity Financings (Narrative) (Details) - USD ($) shares in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Long-Term Debt And Equity Financings [Line Items] | ||
Stock Issued During Period, Shares, New Issues | 0.3 | 0.3 |
Issuance of common stock | $ 19,000,000 | $ 17,000,000 |
Stock Issued During Period, Shares, Other | 0.8 | 0.7 |
Noncash financing activity - Issuance of common stock for stock-based compensation | $ 54,000,000 | $ 35,000,000 |
Union Electric Company | Secured Debt | First Mortgage Bonds, 3.50%, Due 2029 - $450 Issuance | ||
Long-Term Debt And Equity Financings [Line Items] | ||
Total principal amount of notes | $ 450,000,000 | |
State interest rate | 3.50% | |
Proceeds from Issuance of Secured Debt | $ 447,000,000 | |
Union Electric Company | Secured Debt | Senior Secured Notes 6.70% Due 2019 | ||
Long-Term Debt And Equity Financings [Line Items] | ||
State interest rate | 6.70% | |
Repayments of other long-term debt | $ 329,000,000 |
Other Income, Net (Detail)
Other Income, Net (Detail) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Other Nonoperating Income (Expense) [Line Items] | ||
Allowance for equity funds used during construction | $ 6 | $ 5 |
Interest income on industrial development revenue bonds | 6 | 6 |
Interest income | 2 | 2 |
Non-service cost components of net periodic benefit income | 22 | 16 |
Other income | 2 | 1 |
Donations | (6) | (5) |
Other expense | (3) | (2) |
Other Income (Expense), Net | 29 | 23 |
Union Electric Company | ||
Other Nonoperating Income (Expense) [Line Items] | ||
Allowance for equity funds used during construction | 4 | 4 |
Interest income on industrial development revenue bonds | 6 | 6 |
Non-service cost components of net periodic benefit income | 4 | 5 |
Other income | 1 | 1 |
Donations | (2) | (1) |
Other expense | (1) | (2) |
Other Income (Expense), Net | 12 | 13 |
Defined Benefit Plan, Non-service Cost or Income Components - Tracker | 7 | 4 |
Ameren Illinois Company | ||
Other Nonoperating Income (Expense) [Line Items] | ||
Allowance for equity funds used during construction | 2 | 1 |
Interest income | 2 | 2 |
Non-service cost components of net periodic benefit income | 12 | 7 |
Other income | 1 | 0 |
Donations | (4) | (4) |
Other expense | (2) | 0 |
Other Income (Expense), Net | $ 11 | $ 6 |
Derivative Financial Instrume_3
Derivative Financial Instruments (Open Gross Derivative Volumes By Commodity Type) (Detail) gal in Millions, MWh in Millions, MMBTU in Millions | Mar. 31, 2019MWhgalMMBTU | Dec. 31, 2018MWhgalMMBTU |
Fuel Oils | ||
Derivative [Line Items] | ||
Quantity | gal | 65 | 66 |
Natural Gas | ||
Derivative [Line Items] | ||
Quantity | MMBTU | 174 | 173 |
Power | ||
Derivative [Line Items] | ||
Quantity | MWh | 10 | 9 |
Union Electric Company | Fuel Oils | ||
Derivative [Line Items] | ||
Quantity | gal | 65 | 66 |
Union Electric Company | Natural Gas | ||
Derivative [Line Items] | ||
Quantity | MMBTU | 18 | 19 |
Union Electric Company | Power | ||
Derivative [Line Items] | ||
Quantity | MWh | 2 | 1 |
Ameren Illinois Company | Natural Gas | ||
Derivative [Line Items] | ||
Quantity | MMBTU | 156 | 154 |
Ameren Illinois Company | Power | ||
Derivative [Line Items] | ||
Quantity | MWh | 8 | 8 |
Derivative Financial Instrume_4
Derivative Financial Instruments (Derivative Instruments Carrying Value) (Detail) - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018 |
Derivative [Line Items] | ||
Derivative liabilities | $ 206 | |
Not Designated As Hedging Instrument | ||
Derivative [Line Items] | ||
Derivative assets | 17 | $ 15 |
Derivative liabilities | 219 | |
Not Designated As Hedging Instrument | Fuel Oils | Other Current Assets | ||
Derivative [Line Items] | ||
Derivative assets | 5 | 3 |
Not Designated As Hedging Instrument | Fuel Oils | Other Assets | ||
Derivative [Line Items] | ||
Derivative assets | 4 | 5 |
Not Designated As Hedging Instrument | Fuel Oils | Other Current Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 3 | 4 |
Not Designated As Hedging Instrument | Fuel Oils | Other Deferred Credits And Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 4 | 9 |
Not Designated As Hedging Instrument | Natural Gas | Other Current Assets | ||
Derivative [Line Items] | ||
Derivative assets | 3 | 1 |
Not Designated As Hedging Instrument | Natural Gas | Other Assets | ||
Derivative [Line Items] | ||
Derivative assets | 3 | 2 |
Not Designated As Hedging Instrument | Natural Gas | Other Current Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 8 | 12 |
Not Designated As Hedging Instrument | Natural Gas | Other Deferred Credits And Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 5 | 7 |
Not Designated As Hedging Instrument | Power | Other Current Assets | ||
Derivative [Line Items] | ||
Derivative assets | 1 | 4 |
Not Designated As Hedging Instrument | Power | Other Assets | ||
Derivative [Line Items] | ||
Derivative assets | 1 | |
Not Designated As Hedging Instrument | Power | Other Current Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 16 | 18 |
Not Designated As Hedging Instrument | Power | Other Deferred Credits And Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 170 | 169 |
Union Electric Company | Not Designated As Hedging Instrument | ||
Derivative [Line Items] | ||
Derivative assets | 11 | 12 |
Derivative liabilities | 12 | 22 |
Union Electric Company | Not Designated As Hedging Instrument | Fuel Oils | Other Current Assets | ||
Derivative [Line Items] | ||
Derivative assets | 5 | 3 |
Union Electric Company | Not Designated As Hedging Instrument | Fuel Oils | Other Assets | ||
Derivative [Line Items] | ||
Derivative assets | 4 | 5 |
Union Electric Company | Not Designated As Hedging Instrument | Fuel Oils | Other Current Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 3 | 4 |
Union Electric Company | Not Designated As Hedging Instrument | Fuel Oils | Other Deferred Credits And Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 4 | 9 |
Union Electric Company | Not Designated As Hedging Instrument | Natural Gas | Other Current Assets | ||
Derivative [Line Items] | ||
Derivative assets | 0 | 0 |
Union Electric Company | Not Designated As Hedging Instrument | Natural Gas | Other Assets | ||
Derivative [Line Items] | ||
Derivative assets | 0 | 0 |
Union Electric Company | Not Designated As Hedging Instrument | Natural Gas | Other Current Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 2 | 4 |
Union Electric Company | Not Designated As Hedging Instrument | Natural Gas | Other Deferred Credits And Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 1 | 1 |
Union Electric Company | Not Designated As Hedging Instrument | Power | Other Current Assets | ||
Derivative [Line Items] | ||
Derivative assets | 1 | 4 |
Union Electric Company | Not Designated As Hedging Instrument | Power | Other Assets | ||
Derivative [Line Items] | ||
Derivative assets | 1 | |
Union Electric Company | Not Designated As Hedging Instrument | Power | Other Current Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 2 | 4 |
Union Electric Company | Not Designated As Hedging Instrument | Power | Other Deferred Credits And Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 0 | 0 |
Ameren Illinois Company | Not Designated As Hedging Instrument | ||
Derivative [Line Items] | ||
Derivative assets | 6 | 3 |
Derivative liabilities | 194 | 197 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Fuel Oils | Other Current Assets | ||
Derivative [Line Items] | ||
Derivative assets | 0 | 0 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Fuel Oils | Other Assets | ||
Derivative [Line Items] | ||
Derivative assets | 0 | 0 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Fuel Oils | Other Current Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 0 | 0 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Fuel Oils | Other Deferred Credits And Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 0 | 0 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Natural Gas | Other Current Assets | ||
Derivative [Line Items] | ||
Derivative assets | 3 | 1 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Natural Gas | Other Assets | ||
Derivative [Line Items] | ||
Derivative assets | 3 | 2 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Natural Gas | Other Current Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 6 | 8 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Natural Gas | Other Deferred Credits And Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 4 | 6 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Power | Other Current Assets | ||
Derivative [Line Items] | ||
Derivative assets | 0 | 0 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Power | Other Assets | ||
Derivative [Line Items] | ||
Derivative assets | 0 | |
Ameren Illinois Company | Not Designated As Hedging Instrument | Power | Other Current Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | 14 | 14 |
Ameren Illinois Company | Not Designated As Hedging Instrument | Power | Other Deferred Credits And Liabilities | ||
Derivative [Line Items] | ||
Derivative liabilities | $ 170 | $ 169 |
Derivative Financial Instrume_5
Derivative Financial Instruments (Derivative Instruments With Credit Risk-Related Contingent Features) (Detail) $ in Millions | Mar. 31, 2019USD ($) |
Derivative [Line Items] | |
Aggregate Fair Value of Derivative Liabilities | $ 103 |
Cash Collateral Posted | 4 |
Potential Aggregate Amount of Additional Collateral Required | 87 |
Union Electric Company | |
Derivative [Line Items] | |
Aggregate Fair Value of Derivative Liabilities | 64 |
Cash Collateral Posted | 4 |
Potential Aggregate Amount of Additional Collateral Required | 58 |
Ameren Illinois Company | |
Derivative [Line Items] | |
Aggregate Fair Value of Derivative Liabilities | 39 |
Cash Collateral Posted | 0 |
Potential Aggregate Amount of Additional Collateral Required | $ 29 |
Fair Value Measurements (Schedu
Fair Value Measurements (Schedule Of Fair Value Hierarchy Of Assets And Liabilities Measured At Fair Value On Recurring Basis) (Detail) - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018 |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | $ 748 | $ 679 |
Assets fair value | 765 | 694 |
Derivative liabilities | (206) | |
Excluded receivables, payables, and accrued income, net | 6 | 5 |
Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 488 | 427 |
Assets fair value | 490 | 428 |
Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 260 | 252 |
Assets fair value | 263 | 255 |
Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Assets fair value | 12 | 11 |
Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 17 | 15 |
Derivative liabilities | (206) | (219) |
Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 2 | 1 |
Derivative liabilities | (1) | (2) |
Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 3 | 3 |
Derivative liabilities | (10) | (16) |
Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 12 | 11 |
Derivative liabilities | (195) | (201) |
Fuel Oils | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 9 | 8 |
Derivative liabilities | (7) | (13) |
Fuel Oils | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 2 | 1 |
Derivative liabilities | (1) | (2) |
Fuel Oils | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 0 | 0 |
Derivative liabilities | 0 | 0 |
Fuel Oils | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 7 | 7 |
Derivative liabilities | (6) | (11) |
Power | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 2 | 4 |
Derivative liabilities | (186) | (187) |
Power | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 0 | 0 |
Derivative liabilities | 0 | 0 |
Power | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 0 | 1 |
Derivative liabilities | 0 | (1) |
Power | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 2 | 3 |
Derivative liabilities | (186) | (186) |
Natural Gas | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 6 | 3 |
Derivative liabilities | (13) | (19) |
Natural Gas | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 0 | 0 |
Derivative liabilities | 0 | 0 |
Natural Gas | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 3 | 2 |
Derivative liabilities | (10) | (15) |
Natural Gas | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 3 | 1 |
Derivative liabilities | (3) | (4) |
Equity Securities | U.S. large capitalization | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 488 | 427 |
Equity Securities | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | U.S. large capitalization | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 488 | 427 |
Equity Securities | Significant Other Observable Inputs (Level 2) | U.S. large capitalization | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Equity Securities | Significant Other Unobservable Inputs (Level 3) | U.S. large capitalization | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Debt Securities | Corporate bonds | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 76 | 72 |
Debt Securities | US treasury and government securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 151 | 148 |
Debt Securities | Other Debt Securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 33 | 32 |
Debt Securities | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | Corporate bonds | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Debt Securities | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | US treasury and government securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Debt Securities | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | Other Debt Securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Debt Securities | Significant Other Observable Inputs (Level 2) | Corporate bonds | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 76 | 72 |
Debt Securities | Significant Other Observable Inputs (Level 2) | US treasury and government securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 151 | 148 |
Debt Securities | Significant Other Observable Inputs (Level 2) | Other Debt Securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 33 | 32 |
Debt Securities | Significant Other Unobservable Inputs (Level 3) | Corporate bonds | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Debt Securities | Significant Other Unobservable Inputs (Level 3) | US treasury and government securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Debt Securities | Significant Other Unobservable Inputs (Level 3) | Other Debt Securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Union Electric Company | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 748 | 679 |
Assets fair value | 759 | 691 |
Excluded receivables, payables, and accrued income, net | 6 | 4 |
Union Electric Company | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 488 | 427 |
Assets fair value | 490 | 428 |
Union Electric Company | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 260 | 252 |
Assets fair value | 260 | 253 |
Union Electric Company | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Assets fair value | 9 | 10 |
Union Electric Company | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 11 | 12 |
Derivative liabilities | (12) | (22) |
Union Electric Company | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 2 | 1 |
Derivative liabilities | (1) | (2) |
Union Electric Company | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 0 | 1 |
Derivative liabilities | (3) | (6) |
Union Electric Company | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 9 | 10 |
Derivative liabilities | (8) | (14) |
Union Electric Company | Fuel Oils | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 9 | 8 |
Derivative liabilities | (7) | (13) |
Union Electric Company | Fuel Oils | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 2 | 1 |
Derivative liabilities | (1) | (2) |
Union Electric Company | Fuel Oils | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 0 | 0 |
Derivative liabilities | 0 | 0 |
Union Electric Company | Fuel Oils | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 7 | 7 |
Derivative liabilities | (6) | (11) |
Union Electric Company | Power | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 2 | 4 |
Derivative liabilities | (2) | (4) |
Union Electric Company | Power | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 0 | 0 |
Derivative liabilities | 0 | 0 |
Union Electric Company | Power | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 0 | 1 |
Derivative liabilities | 0 | (1) |
Union Electric Company | Power | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 2 | 3 |
Derivative liabilities | (2) | (3) |
Union Electric Company | Natural Gas | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | (3) | (5) |
Union Electric Company | Natural Gas | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | 0 | 0 |
Union Electric Company | Natural Gas | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | (3) | (5) |
Union Electric Company | Natural Gas | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | 0 | 0 |
Union Electric Company | Equity Securities | U.S. large capitalization | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 488 | 427 |
Union Electric Company | Equity Securities | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | U.S. large capitalization | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 488 | 427 |
Union Electric Company | Equity Securities | Significant Other Observable Inputs (Level 2) | U.S. large capitalization | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Union Electric Company | Equity Securities | Significant Other Unobservable Inputs (Level 3) | U.S. large capitalization | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Union Electric Company | Debt Securities | Corporate bonds | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 76 | 72 |
Union Electric Company | Debt Securities | US treasury and government securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 151 | 148 |
Union Electric Company | Debt Securities | Other Debt Securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 33 | 32 |
Union Electric Company | Debt Securities | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | Corporate bonds | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Union Electric Company | Debt Securities | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | US treasury and government securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Union Electric Company | Debt Securities | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | Other Debt Securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Union Electric Company | Debt Securities | Significant Other Observable Inputs (Level 2) | Corporate bonds | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 76 | 72 |
Union Electric Company | Debt Securities | Significant Other Observable Inputs (Level 2) | US treasury and government securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 151 | 148 |
Union Electric Company | Debt Securities | Significant Other Observable Inputs (Level 2) | Other Debt Securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 33 | 32 |
Union Electric Company | Debt Securities | Significant Other Unobservable Inputs (Level 3) | Corporate bonds | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Union Electric Company | Debt Securities | Significant Other Unobservable Inputs (Level 3) | US treasury and government securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Union Electric Company | Debt Securities | Significant Other Unobservable Inputs (Level 3) | Other Debt Securities | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Nuclear Decommissioning Trust Fund | 0 | 0 |
Ameren Illinois Company | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | (194) | (197) |
Ameren Illinois Company | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | 0 | 0 |
Ameren Illinois Company | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | (7) | (10) |
Ameren Illinois Company | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | (187) | (187) |
Ameren Illinois Company | Power | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | (184) | (183) |
Ameren Illinois Company | Power | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | 0 | 0 |
Ameren Illinois Company | Power | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | 0 | 0 |
Ameren Illinois Company | Power | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative liabilities | (184) | (183) |
Ameren Illinois Company | Natural Gas | Commodity Contract | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 6 | 3 |
Derivative liabilities | (10) | (14) |
Ameren Illinois Company | Natural Gas | Commodity Contract | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 0 | 0 |
Derivative liabilities | 0 | 0 |
Ameren Illinois Company | Natural Gas | Commodity Contract | Significant Other Observable Inputs (Level 2) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 3 | 2 |
Derivative liabilities | (7) | (10) |
Ameren Illinois Company | Natural Gas | Commodity Contract | Significant Other Unobservable Inputs (Level 3) | ||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
Derivative assets | 3 | 1 |
Derivative liabilities | $ (3) | $ (4) |
Fair Value Measurements (Sche_2
Fair Value Measurements (Schedule Of Changes In The Fair Value Of Financial Assets And Liabilities Classified As Level Three In The Fair Value Hierarchy) (Detail) - Power - USD ($) $ in Millions | 3 Months Ended | |||
Mar. 31, 2019 | Mar. 31, 2018 | Dec. 31, 2018 | Dec. 31, 2017 | |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs | $ (184) | $ (187) | $ (183) | $ (188) |
Included in regulatory assets/liabilities | (4) | (1) | ||
Settlements | 3 | 2 | ||
Change in unrealized gains (losses) related to assets/liabilities held at period end | (4) | 0 | ||
Union Electric Company | ||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs | 0 | 4 | 0 | 7 |
Included in regulatory assets/liabilities | 0 | (2) | ||
Settlements | 0 | (1) | ||
Change in unrealized gains (losses) related to assets/liabilities held at period end | 0 | (1) | ||
Ameren Illinois Company | ||||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs | (184) | (191) | $ (183) | $ (195) |
Included in regulatory assets/liabilities | (4) | 1 | ||
Settlements | 3 | 3 | ||
Change in unrealized gains (losses) related to assets/liabilities held at period end | $ (4) | $ 1 |
Fair Value Measurements (Sche_3
Fair Value Measurements (Schedule Of Valuation Process And Unobservable Inputs) (Detail) $ in Millions | Mar. 31, 2019USD ($)$ / MMBTU$ / MWh | Dec. 31, 2018USD ($) | Mar. 31, 2018$ / MMBTU$ / MWh |
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Derivative liabilities | $ | $ (206) | ||
Power | Derivative Assets | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Derivative assets | $ | 2 | $ 3 | |
Power | Derivative Liabilities | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Derivative liabilities | $ | $ (186) | $ (186) | |
Commodity Forward Price | Power | Discounted Cash Flow | Minimum | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | 23 | ||
Commodity Forward Price | Power | Discounted Cash Flow | Maximum | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | 39 | ||
Commodity Forward Price | Power | Discounted Cash Flow | Weighted Average | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | 28 | ||
Nodal Basis | Power | Discounted Cash Flow | Minimum | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | (9) | (9) | |
Nodal Basis | Power | Discounted Cash Flow | Maximum | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | 0 | 0 | |
Nodal Basis | Power | Discounted Cash Flow | Weighted Average | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | (2) | (2) | |
Quoted Price | Power | Discounted Cash Flow | Minimum | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | 24 | ||
Quoted Price | Power | Discounted Cash Flow | Maximum | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | 38 | ||
Quoted Price | Power | Discounted Cash Flow | Weighted Average | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | 28 | ||
Commodity Future Price | Power | Fundamental Energy Production Model | Minimum | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | $ / MMBTU | 3 | 3 | |
Commodity Future Price | Power | Fundamental Energy Production Model | Maximum | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | $ / MMBTU | 4 | 4 | |
Commodity Future Price | Power | Fundamental Energy Production Model | Weighted Average | |||
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||
Measurement input | $ / MMBTU | 3 | 3 |
Fair Value Measurements (Sche_4
Fair Value Measurements (Schedule Of Carrying Amounts And Estimated Fair Values Of Financial Assets and Liabilities) (Detail) - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018 | Mar. 31, 2018 | Dec. 31, 2017 |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt | $ 799 | $ 597 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 118 | 107 | $ 89 | $ 68 |
Union Electric Company | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt | 55 | 55 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 12 | 8 | 10 | 7 |
Ameren Illinois Company | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt | 126 | 72 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 93 | 80 | $ 52 | $ 41 |
Carrying Amount | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Available-for-sale Securities and Held-to-maturity Securities | 270 | 270 | ||
Short-term Debt | 799 | 597 | ||
Long-term debt (including current portion) | 8,557 | 8,439 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 118 | 107 | ||
Debt Issuance Costs, Net | 62 | 58 | ||
Carrying Amount | Union Electric Company | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Available-for-sale Securities and Held-to-maturity Securities | 270 | 270 | ||
Short-term Debt | 55 | 55 | ||
Long-term debt (including current portion) | 4,116 | 3,998 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 12 | 8 | ||
Debt Issuance Costs, Net | 25 | 22 | ||
Carrying Amount | Ameren Illinois Company | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt | 126 | 72 | ||
Long-term debt (including current portion) | 3,296 | 3,296 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 93 | 80 | ||
Debt Issuance Costs, Net | 32 | 31 | ||
Fair Value | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 799 | 597 | ||
Investments, Fair Value Disclosure | 270 | 270 | ||
Long-term Debt, Fair Value | 9,070 | 8,669 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 118 | 107 | ||
Fair Value | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 0 | 0 | ||
Investments, Fair Value Disclosure | 0 | 0 | ||
Long-term Debt, Fair Value | 0 | 0 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 118 | 107 | ||
Fair Value | Significant Other Observable Inputs (Level 2) | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 799 | 597 | ||
Investments, Fair Value Disclosure | 270 | 270 | ||
Long-term Debt, Fair Value | 8,623 | 8,240 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 0 | 0 | ||
Fair Value | Significant Other Unobservable Inputs (Level 3) | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 0 | 0 | ||
Investments, Fair Value Disclosure | 0 | 0 | ||
Long-term Debt, Fair Value | 447 | 429 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 0 | 0 | ||
Fair Value | Union Electric Company | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 55 | 55 | ||
Investments, Fair Value Disclosure | 270 | 270 | ||
Long-term Debt, Fair Value | 4,404 | 4,156 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 12 | 8 | ||
Fair Value | Union Electric Company | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 0 | 0 | ||
Investments, Fair Value Disclosure | 0 | 0 | ||
Long-term Debt, Fair Value | 0 | 0 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 12 | 8 | ||
Fair Value | Union Electric Company | Significant Other Observable Inputs (Level 2) | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 55 | 55 | ||
Investments, Fair Value Disclosure | 270 | 270 | ||
Long-term Debt, Fair Value | 4,404 | 4,156 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 0 | 0 | ||
Fair Value | Union Electric Company | Significant Other Unobservable Inputs (Level 3) | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 0 | 0 | ||
Investments, Fair Value Disclosure | 0 | 0 | ||
Long-term Debt, Fair Value | 0 | 0 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 0 | 0 | ||
Fair Value | Ameren Illinois Company | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 126 | 72 | ||
Long-term Debt, Fair Value | 3,515 | 3,391 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 93 | 80 | ||
Fair Value | Ameren Illinois Company | Quoted Prices In Active Markets For Identical Assets or Liabilities (Level 1) | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 0 | 0 | ||
Long-term Debt, Fair Value | 0 | 0 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 93 | 80 | ||
Fair Value | Ameren Illinois Company | Significant Other Observable Inputs (Level 2) | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 126 | 72 | ||
Long-term Debt, Fair Value | 3,515 | 3,391 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 0 | 0 | ||
Fair Value | Ameren Illinois Company | Significant Other Unobservable Inputs (Level 3) | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Short-term Debt, Fair Value | 0 | 0 | ||
Long-term Debt, Fair Value | 0 | 0 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | $ 0 | $ 0 |
Related Party Transactions (Sch
Related Party Transactions (Schedule of Related Party Transactions) (Detail) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Related Party Transaction [Line Items] | ||
Operating Revenues | $ 0 | $ 0 |
Union Electric Company | ||
Related Party Transaction [Line Items] | ||
Operating Expenses | 32 | 33 |
Ameren Illinois Company | ||
Related Party Transaction [Line Items] | ||
Operating Revenues | 0 | 0 |
Operating Expenses | 31 | 32 |
Ameren Missouri Power Supply Agreements with Ameren Illinois | Union Electric Company | ||
Related Party Transaction [Line Items] | ||
Operating Revenues | 1 | 3 |
Ameren Missouri and Ameren Illinois Rent and Facility Services | Union Electric Company | ||
Related Party Transaction [Line Items] | ||
Operating Revenues | 7 | 5 |
Operating Expenses | 1 | 1 |
Ameren Missouri and Ameren Illinois Rent and Facility Services | Ameren Illinois Company | ||
Related Party Transaction [Line Items] | ||
Operating Revenues | 1 | 1 |
Operating Expenses | 1 | 2 |
Total Related Party Operating Revenues [Member] | Union Electric Company | ||
Related Party Transaction [Line Items] | ||
Operating Revenues | 7 | 8 |
Total Related Party Operating Revenues [Member] | Ameren Illinois Company | ||
Related Party Transaction [Line Items] | ||
Operating Revenues | 1 | 1 |
Ameren Missouri and Ameren Illinois miscellaneous support services | Union Electric Company | ||
Related Party Transaction [Line Items] | ||
Operating Revenues | 1 | 1 |
Ameren Missouri and Ameren Illinois miscellaneous support services | Ameren Illinois Company | ||
Related Party Transaction [Line Items] | ||
Operating Revenues | 1 | 1 |
Ameren Illinois Power Supply Agreements with Ameren Missouri | Ameren Illinois Company | ||
Related Party Transaction [Line Items] | ||
Operating Expenses | 1 | 3 |
Ameren Illinois transmission services from ATXI | Ameren Illinois Company | ||
Related Party Transaction [Line Items] | ||
Operating Expenses | 1 | 1 |
Purchased Power | Ameren Illinois Company | ||
Related Party Transaction [Line Items] | ||
Operating Expenses | 1 | 3 |
Ameren Services Support Services Agreement | Union Electric Company | ||
Related Party Transaction [Line Items] | ||
Operating Expenses | 32 | 33 |
Ameren Services Support Services Agreement | Ameren Illinois Company | ||
Related Party Transaction [Line Items] | ||
Operating Expenses | 30 | 30 |
Money Pool [Member] | Union Electric Company | ||
Related Party Transaction [Line Items] | ||
Interest Charges | 0 | 1 |
Money Pool [Member] | Ameren Illinois Company | ||
Related Party Transaction [Line Items] | ||
Interest Charges | $ 0 | $ 1 |
Related Party Transactions Narr
Related Party Transactions Narrative (Details) - April 2019 Procurement - Ameren Illinois Company - Ameren Illinois Power Supply Agreements with Ameren Missouri | 3 Months Ended |
Mar. 31, 2019MWh$ / MWh | |
Related Party Transaction [Line Items] | |
Long-term Contract for Purchase of Electric Power, Related Party Contract, Fixed Power | MWh | 288,000 |
Long-term Contract for Purchase of Electric Power, Related Party Contract, Fixed Power, Rate | $ / MWh | 35 |
Commitments And Contingencies_2
Commitments And Contingencies (Other Obligations) (Detail) $ in Millions | 3 Months Ended |
Mar. 31, 2019USD ($)MWh | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | $ 600 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 460 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 307 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 146 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 81 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 161 |
Unrecorded Unconditional Purchase Obligation | 1,755 |
Coal | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 279 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 160 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 121 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 72 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 0 |
Unrecorded Unconditional Purchase Obligation | 632 |
Natural Gas | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 154 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 158 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 85 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 32 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 8 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 34 |
Unrecorded Unconditional Purchase Obligation | 471 |
Nuclear Fuel | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 25 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 43 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 58 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 13 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 41 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 29 |
Unrecorded Unconditional Purchase Obligation | 209 |
Purchased Power | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 88 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 54 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 10 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 0 |
Unrecorded Unconditional Purchase Obligation | $ 152 |
Amount of Megawatts | MWh | 102 |
Methane Gas | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | $ 2 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 27 |
Unrecorded Unconditional Purchase Obligation | 41 |
Other Purchased Fuel | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 52 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 42 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 30 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 26 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 29 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 71 |
Unrecorded Unconditional Purchase Obligation | 250 |
Union Electric Company | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 378 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 269 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 223 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 119 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 78 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 124 |
Unrecorded Unconditional Purchase Obligation | 1,191 |
Union Electric Company | Coal | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 279 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 160 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 121 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 72 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 0 |
Unrecorded Unconditional Purchase Obligation | 632 |
Union Electric Company | Natural Gas | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 33 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 34 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 16 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 5 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 5 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 13 |
Unrecorded Unconditional Purchase Obligation | 106 |
Union Electric Company | Nuclear Fuel | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 25 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 43 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 58 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 13 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 41 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 29 |
Unrecorded Unconditional Purchase Obligation | 209 |
Union Electric Company | Purchased Power | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 0 |
Unrecorded Unconditional Purchase Obligation | $ 0 |
Amount of Megawatts | MWh | 102 |
Union Electric Company | Methane Gas | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | $ 2 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 27 |
Unrecorded Unconditional Purchase Obligation | 41 |
Union Electric Company | Other Purchased Fuel | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 39 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 29 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 25 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 26 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 29 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 55 |
Unrecorded Unconditional Purchase Obligation | 203 |
Ameren Illinois Company | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 214 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 182 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 79 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 27 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 21 |
Unrecorded Unconditional Purchase Obligation | 526 |
Ameren Illinois Company | Coal | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 0 |
Unrecorded Unconditional Purchase Obligation | 0 |
Ameren Illinois Company | Natural Gas | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 121 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 124 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 69 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 27 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 3 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 21 |
Unrecorded Unconditional Purchase Obligation | 365 |
Ameren Illinois Company | Nuclear Fuel | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 0 |
Unrecorded Unconditional Purchase Obligation | 0 |
Ameren Illinois Company | Purchased Power | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 88 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 54 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 10 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 0 |
Unrecorded Unconditional Purchase Obligation | 152 |
Ameren Illinois Company | Methane Gas | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 0 |
Unrecorded Unconditional Purchase Obligation | 0 |
Ameren Illinois Company | Other Purchased Fuel | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months | 5 |
Unrecorded Unconditional Purchase Obligation, Due within Two Years | 4 |
Unrecorded Unconditional Purchase Obligation, Due within Three Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Four Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due within Five Years | 0 |
Unrecorded Unconditional Purchase Obligation, Due after Five Years | 0 |
Unrecorded Unconditional Purchase Obligation | 9 |
Ameren Illinois Company | Zero Emission Credits | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Unrecorded Unconditional Purchase Obligation | $ 10 |
Ameren Illinois Company | April 2019 Procurement | |
Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] | |
Amount of Megawatthours | MWh | 3,704,000 |
Long-term Purchase Commitment, Amount | $ 108 |
Commitments And Contingencies_3
Commitments And Contingencies (Environmental Matters) (Detail) $ in Millions | Mar. 31, 2019USD ($)scrubbersite | Dec. 31, 2018USD ($) |
Loss Contingencies [Line Items] | ||
Percentage of Rate Base Related to Carbon Dioxide Energy Centers | 16.00% | |
Asset Retirement Obligation | $ 653 | $ 650 |
Minimum | ||
Loss Contingencies [Line Items] | ||
Estimated capital costs to comply with existing and known federal and state air emissions regulations | 300 | |
Maximum | ||
Loss Contingencies [Line Items] | ||
Estimated capital costs to comply with existing and known federal and state air emissions regulations | 400 | |
Union Electric Company | ||
Loss Contingencies [Line Items] | ||
Percentage of Rate Base Related to Carbon Dioxide Energy Centers | 32.00% | |
Asset Retirement Obligation | $ 649 | $ 646 |
Number of Energy Center Scrubbers | scrubber | 2 | |
Union Electric Company | Minimum | ||
Loss Contingencies [Line Items] | ||
Estimated capital costs to comply with existing and known federal and state air emissions regulations | $ 300 | |
Union Electric Company | Maximum | ||
Loss Contingencies [Line Items] | ||
Estimated capital costs to comply with existing and known federal and state air emissions regulations | 400 | |
Ameren Illinois Company | ||
Loss Contingencies [Line Items] | ||
Asset Retirement Obligation | 4 | $ 4 |
Coal Combustion Residuals Estimate | Union Electric Company | Minimum | ||
Loss Contingencies [Line Items] | ||
Estimated capital costs to comply with existing and known federal and state air emissions regulations | 150 | |
Coal Combustion Residuals Estimate | Union Electric Company | Maximum | ||
Loss Contingencies [Line Items] | ||
Estimated capital costs to comply with existing and known federal and state air emissions regulations | 200 | |
Manufactured Gas Plant | ||
Loss Contingencies [Line Items] | ||
Accrual for environmental loss contingencies | $ 145 | |
Manufactured Gas Plant | Ameren Illinois Company | ||
Loss Contingencies [Line Items] | ||
Number of remediation sites | site | 44 | |
Accrual for environmental loss contingencies | $ 145 | |
Manufactured Gas Plant | Ameren Illinois Company | Minimum | ||
Loss Contingencies [Line Items] | ||
Estimate of possible loss | 145 | |
Manufactured Gas Plant | Ameren Illinois Company | Maximum | ||
Loss Contingencies [Line Items] | ||
Estimate of possible loss | 215 | |
New CCR Rules Estimate | ||
Loss Contingencies [Line Items] | ||
Asset Retirement Obligation | 131 | |
New CCR Rules Estimate | Union Electric Company | ||
Loss Contingencies [Line Items] | ||
Asset Retirement Obligation | $ 131 |
Callaway Energy Center (Narrati
Callaway Energy Center (Narrative) (Detail) $ in Millions | 3 Months Ended |
Mar. 31, 2019USD ($) | |
Nuclear Plant | |
Nuclear Waste Matters [Line Items] | |
Annual decommissioning costs included in costs of service | $ 7 |
Callaway Energy Center (Insuran
Callaway Energy Center (Insurance Disclosure) (Detail) | 3 Months Ended |
Mar. 31, 2019USD ($) | |
Nuclear Waste Matters [Line Items] | |
Number of weeks of coverage after the first twelve weeks of an outage | 1 year |
Threshold for which a retrospective assessment for a covered loss is necessary | $ 450,000,000 |
Annual payment in the event of an incident at any licensed commercial reactor | 21,000,000 |
Amount of weekly indemnity coverage commencing eight weeks after power outage | 4,500,000 |
Amount of additional weekly indemnity coverage commencing after initial indemnity coverage | $ 3,600,000 |
Inflationary adjustment prescribed by most recent Price-Anderson Act renewal, in years | 5 years |
Aggregate nuclear power industry insurance policy limit for losses from terrorist attacks within twelve month period | $ 3,200,000,000 |
Number Of Additional Weeks After Initial Indemnity Coverage For Power Outage | 1 year 4 months 10 days |
Public Liability And Nuclear Worker Liability - American Nuclear Insurers | |
Nuclear Waste Matters [Line Items] | |
Maximum Coverages | $ 450,000,000 |
Maximum Assessments for Single Incidents | 0 |
Public Liability And Nuclear Worker Liability - Pool Participation | |
Nuclear Waste Matters [Line Items] | |
Maximum Coverages | 13,623,000,000 |
Maximum Assessments for Single Incidents | 138,000,000 |
Public Liability | |
Nuclear Waste Matters [Line Items] | |
Maximum Coverages | 14,073,000,000 |
Maximum Assessments for Single Incidents | 138,000,000 |
Property Damage - Nuclear Electric Insurance Ltd | |
Nuclear Waste Matters [Line Items] | |
Maximum Coverages | 3,200,000,000 |
Maximum Assessments for Single Incidents | 28,000,000 |
Replacement Power - Nuclear Electric Insurance Ltd | |
Nuclear Waste Matters [Line Items] | |
Maximum Coverages | 490,000,000 |
Maximum Assessments for Single Incidents | 7,000,000 |
Amount of weekly indemnity coverage thereafter not exceeding policy limit | 490,000,000 |
Sub-limit of for non-nuclear events | 328,000,000 |
Property Damage European Mutual Association for Nuclear Insurance | |
Nuclear Waste Matters [Line Items] | |
Maximum Coverages | 490,000,000 |
Radiation Event | |
Nuclear Waste Matters [Line Items] | |
Maximum Coverages | 2,700,000,000 |
Non-radiation event | |
Nuclear Waste Matters [Line Items] | |
Maximum Coverages | 2,300,000,000 |
Aggregate nuclear power industry insurance policy limit for losses from terrorist attacks within twelve month period | $ 1,800,000,000 |
Retirement Benefits (Components
Retirement Benefits (Components Of Net Periodic Benefit Cost) (Detail) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Total non-service cost components | $ (22) | $ (16) |
Pension Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Service cost | 22 | 25 |
Interest cost | 47 | 42 |
Expected return on plan assets | (69) | (69) |
Prior service cost (benefit) | 0 | 0 |
Actuarial loss | 6 | 16 |
Total non-service cost components | (16) | (11) |
Net periodic benefit cost | 6 | 14 |
Other Postretirement Benefit Plan, Defined Benefit | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Service cost | 4 | 5 |
Interest cost | 11 | 11 |
Expected return on plan assets | (19) | (19) |
Prior service cost (benefit) | (1) | (1) |
Actuarial loss | (4) | 0 |
Total non-service cost components | (13) | (9) |
Net periodic benefit cost | (9) | (4) |
Union Electric Company | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Total non-service cost components | (4) | (5) |
Union Electric Company | Pension Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | 1 | 5 |
Union Electric Company | Other Postretirement Benefit Plan, Defined Benefit | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | (2) | 0 |
Ameren Illinois Company | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Total non-service cost components | (12) | (7) |
Ameren Illinois Company | Pension Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | 5 | 9 |
Ameren Illinois Company | Other Postretirement Benefit Plan, Defined Benefit | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | $ (7) | $ (4) |
Retirement Benefits Retirement
Retirement Benefits Retirement Benefits (Summary of Benefit Plan Costs Incurred) (Details) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Pension Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | $ 6 | $ 14 |
Pension Plan | Union Electric Company | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | 1 | 5 |
Pension Plan | Ameren Illinois Company | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | 5 | 9 |
Other Postretirement Benefit Plan, Defined Benefit | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | (9) | (4) |
Other Postretirement Benefit Plan, Defined Benefit | Union Electric Company | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | (2) | 0 |
Other Postretirement Benefit Plan, Defined Benefit | Ameren Illinois Company | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Net periodic benefit cost | $ (7) | $ (4) |
Income Taxes Income Taxes (Sche
Income Taxes Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) | 3 Months Ended | |
Mar. 31, 2019Rate | Mar. 31, 2018Rate | |
Income Taxes [Line Items] | ||
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent | 21.00% | 21.00% |
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization of Excess Deferred Taxes, Percent | (7.00%) | (2.00%) |
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depreciation, Percent | 0.00% | 0.00% |
Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Percent | (1.00%) | (1.00%) |
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent | 6.00% | 7.00% |
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent | (7.00%) | (3.00%) |
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent | 0.00% | 0.00% |
Effective Income Tax Rate Reconciliation, Percent | 12.00% | 22.00% |
Union Electric Company | ||
Income Taxes [Line Items] | ||
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent | 21.00% | 21.00% |
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization of Excess Deferred Taxes, Percent | (12.00%) | 0.00% |
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depreciation, Percent | 0.00% | 1.00% |
Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Percent | (1.00%) | (1.00%) |
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent | 4.00% | 4.00% |
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent | 0.00% | 0.00% |
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent | (3.00%) | 0.00% |
Effective Income Tax Rate Reconciliation, Percent | 9.00% | 25.00% |
Ameren Illinois Company | ||
Income Taxes [Line Items] | ||
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent | 21.00% | 21.00% |
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization of Excess Deferred Taxes, Percent | (3.00%) | (3.00%) |
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depreciation, Percent | 0.00% | 0.00% |
Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Percent | (0.00%) | (0.00%) |
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent | 7.00% | 7.00% |
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent | 0.00% | 0.00% |
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent | 0.00% | 0.00% |
Effective Income Tax Rate Reconciliation, Percent | 25.00% | 25.00% |
Supplemental Information (Narra
Supplemental Information (Narrative) (Details) - USD ($) shares in Millions, $ in Millions | 3 Months Ended | ||
Mar. 31, 2019 | Mar. 31, 2018 | Dec. 31, 2018 | |
Supplemental Information [Abstract] | |||
Payables for purchased receivables | $ 38 | $ 33 | |
Deferred Compensation Liability, Classified, Noncurrent | $ 78 | $ 80 | |
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements (in shares) | 1.5 | 1.5 |
Supplemental Information (Cash
Supplemental Information (Cash and Cash Equivalents) (Details) - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018 | Mar. 31, 2018 | Dec. 31, 2017 |
Schedule of Cash and Cash Equivalents Including Restricted Cash [Line Items] | ||||
Cash and cash equivalents | $ 8 | $ 16 | ||
Restricted Cash and Cash Equivalents, Current | 16 | 13 | ||
Restricted Cash and Cash Equivalents, Noncurrent | 87 | 74 | ||
Restricted Cash and Cash Equivalents, Nuclear Decommissioning Trust Fund | 7 | 4 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 118 | 107 | $ 89 | $ 68 |
Union Electric Company | ||||
Schedule of Cash and Cash Equivalents Including Restricted Cash [Line Items] | ||||
Cash and cash equivalents | 0 | 0 | ||
Restricted Cash and Cash Equivalents, Current | 5 | 4 | ||
Restricted Cash and Cash Equivalents, Noncurrent | 0 | 0 | ||
Restricted Cash and Cash Equivalents, Nuclear Decommissioning Trust Fund | 7 | 4 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 12 | 8 | 10 | 7 |
Ameren Illinois Company | ||||
Schedule of Cash and Cash Equivalents Including Restricted Cash [Line Items] | ||||
Cash and cash equivalents | 0 | 0 | ||
Restricted Cash and Cash Equivalents, Current | 6 | 6 | ||
Restricted Cash and Cash Equivalents, Noncurrent | 87 | 74 | ||
Restricted Cash and Cash Equivalents, Nuclear Decommissioning Trust Fund | 0 | 0 | ||
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | $ 93 | $ 80 | $ 52 | $ 41 |
Supplemental Information (Lease
Supplemental Information (Leases - Supplemental Balance Sheet Information) (Details) $ in Millions | 3 Months Ended |
Mar. 31, 2019USD ($) | |
Lessee, Lease, Description [Line Items] | |
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability | $ 38 |
Operating Lease, Right-of-Use Asset | 36 |
Operating Lease, Liability, Current | 7 |
Operating Lease, Liability, Noncurrent | $ 29 |
Operating Lease, Weighted Average Remaining Lease Term | 6 years |
Operating Lease, Weighted Average Discount Rate, Percent | 3.60% |
Union Electric Company | |
Lessee, Lease, Description [Line Items] | |
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability | $ 36 |
Lessee, Operating Lease, Renewal Term | 5 years |
Operating Lease, Right-of-Use Asset | $ 34 |
Operating Lease, Liability, Current | 6 |
Operating Lease, Liability, Noncurrent | $ 28 |
Operating Lease, Weighted Average Remaining Lease Term | 6 years |
Operating Lease, Weighted Average Discount Rate, Percent | 3.60% |
Supplemental Information (Lea_2
Supplemental Information (Leases - Maturities of Operating Lease Liabilities) (Details) $ in Millions | Mar. 31, 2019USD ($) |
Lessee, Lease, Description [Line Items] | |
2019 | $ 6 |
2020 | 7 |
2021 | 7 |
2022 | 6 |
2023 | 5 |
Thereafter | 10 |
Total lease payments | 41 |
Less imputed interest | 5 |
Total | 36 |
Union Electric Company | |
Lessee, Lease, Description [Line Items] | |
2019 | 5 |
2020 | 7 |
2021 | 6 |
2022 | 5 |
2023 | 5 |
Thereafter | 10 |
Total lease payments | 38 |
Less imputed interest | 4 |
Total | $ 34 |
Supplemental Information (Suppl
Supplemental Information (Supplemental Cash Flow Information) (Details) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Supplemental Cash Flow Information [Line Items] | ||
Capital Expenditures Incurred but Not yet Paid | $ 208 | $ 202 |
Net Realized and Unrealized Gain (Loss) on Trading Securities | 64 | (11) |
Union Electric Company | ||
Supplemental Cash Flow Information [Line Items] | ||
Capital Expenditures Incurred but Not yet Paid | 92 | 73 |
Net Realized and Unrealized Gain (Loss) on Trading Securities | 64 | (11) |
Ameren Illinois Company | ||
Supplemental Cash Flow Information [Line Items] | ||
Capital Expenditures Incurred but Not yet Paid | $ 106 | $ 114 |
Supplemental Information (Sched
Supplemental Information (Schedule of Asset Retirement Obligations) (Details) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Dec. 31, 2018 | |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Asset Retirement Obligation | $ 653 | $ 650 |
Liabilities settled | (3) | |
Accretion | 6 | |
Other current liabilities | 301 | 282 |
Union Electric Company | ||
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Asset Retirement Obligation | 649 | 646 |
Liabilities settled | (3) | |
Accretion | 6 | |
Other current liabilities | 128 | 123 |
Ameren Illinois Company | ||
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Asset Retirement Obligation | 4 | 4 |
Liabilities settled | 0 | |
Accretion | 0 | |
Other current liabilities | 129 | 130 |
Asset Retirement Obligation Balance [Member] | ||
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Other current liabilities | 23 | 23 |
Asset Retirement Obligation Balance [Member] | Union Electric Company | ||
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Other current liabilities | $ 23 | $ 23 |
Supplemental Information (Summa
Supplemental Information (Summary of Nonvested Shares Related To Long-Term Incentive Plan) (Details) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended | ||
Mar. 31, 2019 | Mar. 31, 2018 | Dec. 31, 2018 | |
Weighted-average Fair Value per Unit at Grant Date | |||
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount | $ 14 | $ 6 | |
Performance Shares | |||
Share Units | |||
Nonvested at the beginning of the period (in shares) | 682,811 | ||
Granted (in shares) | 288,956 | ||
Forfeitures (in shares) | (2,228) | ||
Undistributed vested units (in shares) | (65,458) | ||
Vested and distributed (in shares) | (176,923) | ||
Nonvested at the end of the period (in shares) | 727,158 | ||
Fully Vested Undistributed to Retirement-eligible employees (in shares) | 333,466 | 619,783 | |
Weighted-average Fair Value per Unit at Grant Date | |||
Weighted-average Fair Value per Unit, Nonvested as of Beginning of year (in dollars per share) | $ 56.58 | ||
Weighted-average Fair Value per Unit, Granted (in dollars per share) | 67.42 | ||
Weighted-average Fair Value per Unit, Forfeitures (in dollars per share) | 65.06 | ||
Weighted-average Fair Value per Unit, Undistributed Vested Units (in dollars per share) | 62.04 | ||
Weighted-average Fair Value per Unit, Vested (in dollars per share) | 44.13 | ||
Weighted-average Fair Value per Unit, Nonvested as of Current period end (in dollars per share) | $ 63.40 | ||
Performance period | 3 years | ||
Closing common share price (in dollars per share) | $ 65.23 | ||
Expected Volatility Rate | 17.00% | ||
Three-year risk-free rate | 2.46% | ||
Volatility rate, minimum | 15.00% | ||
Volatility rate, maximum | 25.00% | ||
Restricted Stock Units (RSUs) | |||
Share Units | |||
Nonvested at the beginning of the period (in shares) | 155,253 | ||
Granted (in shares) | 124,925 | ||
Forfeitures (in shares) | (833) | ||
Undistributed vested units (in shares) | (14,047) | ||
Vested and distributed (in shares) | 0 | ||
Nonvested at the end of the period (in shares) | 265,298 | ||
Fully Vested Undistributed to Retirement-eligible employees (in shares) | 40,604 | 26,557 | |
Weighted-average Fair Value per Unit at Grant Date | |||
Weighted-average Fair Value per Unit, Nonvested as of Beginning of year (in dollars per share) | $ 57.38 | ||
Weighted-average Fair Value per Unit, Granted (in dollars per share) | 65.23 | ||
Weighted-average Fair Value per Unit, Forfeitures (in dollars per share) | 63.16 | ||
Weighted-average Fair Value per Unit, Undistributed Vested Units (in dollars per share) | 61.77 | ||
Weighted-average Fair Value per Unit, Vested (in dollars per share) | 0 | ||
Weighted-average Fair Value per Unit, Nonvested as of Current period end (in dollars per share) | $ 60.64 |
Supplemental Information (Sch_2
Supplemental Information (Schedule Of Excise Taxes) (Detail) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Accounting Policies [Line Items] | ||
Excise tax expense | $ 70 | $ 69 |
Union Electric Company | ||
Accounting Policies [Line Items] | ||
Excise tax expense | 31 | 34 |
Ameren Illinois Company | ||
Accounting Policies [Line Items] | ||
Excise tax expense | $ 39 | $ 35 |
Segment Information (Schedule O
Segment Information (Schedule Of Segment Reporting Information By Segment) (Detail) $ in Millions | 3 Months Ended | |
Mar. 31, 2019USD ($)segment | Mar. 31, 2018USD ($) | |
Segment Reporting Information [Line Items] | ||
Number of Reportable Segments | segment | 4 | |
External revenues | $ 1,556 | $ 1,585 |
Intersegment revenues | 0 | 0 |
Net Income (Loss) Available to Common Stockholders, Basic | 191 | 151 |
Capital expenditures | $ 544 | 579 |
Union Electric Company | ||
Segment Reporting Information [Line Items] | ||
Number of Reportable Segments | segment | 1 | |
Ameren Illinois Company | ||
Segment Reporting Information [Line Items] | ||
Number of Reportable Segments | segment | 3 | |
Ameren Illinois Company | ||
Segment Reporting Information [Line Items] | ||
External revenues | $ 762 | 760 |
Intersegment revenues | 0 | 0 |
Net Income Available to Common Shareholder | 120 | 95 |
Capital expenditures | 267 | 300 |
Operating Segments | Union Electric Company | ||
Segment Reporting Information [Line Items] | ||
External revenues | 751 | 784 |
Intersegment revenues | 7 | 8 |
Net Income Available to Common Shareholder | 39 | 38 |
Capital expenditures | 240 | 249 |
Operating Segments | Ameren Illinois Electric Distribution | ||
Segment Reporting Information [Line Items] | ||
External revenues | 386 | 399 |
Intersegment revenues | 1 | 1 |
Net Income Available to Common Shareholder | 36 | 33 |
Capital expenditures | 124 | 122 |
Operating Segments | Ameren Illinois Gas | ||
Segment Reporting Information [Line Items] | ||
External revenues | 320 | 311 |
Intersegment revenues | 0 | 0 |
Net Income Available to Common Shareholder | 57 | 42 |
Capital expenditures | 51 | 60 |
Operating Segments | Ameren Transmission | ||
Segment Reporting Information [Line Items] | ||
External revenues | 99 | 91 |
Intersegment revenues | 15 | 13 |
Net Income Available to Common Shareholder | 44 | 37 |
Capital expenditures | 121 | 145 |
Operating Segments | Other | ||
Segment Reporting Information [Line Items] | ||
External revenues | 0 | 0 |
Intersegment revenues | 0 | 0 |
Net Income Available to Common Shareholder | 15 | 1 |
Capital expenditures | 10 | 7 |
Operating Segments | Ameren Illinois Company | Ameren Illinois Electric Distribution | ||
Segment Reporting Information [Line Items] | ||
External revenues | 387 | 400 |
Intersegment revenues | 0 | 0 |
Net Income Available to Common Shareholder | 36 | 33 |
Capital expenditures | 124 | 122 |
Operating Segments | Ameren Illinois Company | Ameren Illinois Gas | ||
Segment Reporting Information [Line Items] | ||
External revenues | 320 | 311 |
Intersegment revenues | 0 | 0 |
Net Income Available to Common Shareholder | 57 | 42 |
Capital expenditures | 51 | 60 |
Operating Segments | Ameren Illinois Company | Ameren Illinois Transmission | ||
Segment Reporting Information [Line Items] | ||
External revenues | 55 | 49 |
Intersegment revenues | 15 | 13 |
Net Income Available to Common Shareholder | 27 | 20 |
Capital expenditures | 92 | 118 |
Intersegment Eliminations | ||
Segment Reporting Information [Line Items] | ||
External revenues | 0 | 0 |
Intersegment revenues | (23) | (22) |
Net Income Available to Common Shareholder | 0 | 0 |
Capital expenditures | (2) | (4) |
Intersegment Eliminations | Ameren Illinois Company | ||
Segment Reporting Information [Line Items] | ||
External revenues | 0 | 0 |
Intersegment revenues | (15) | (13) |
Net Income Available to Common Shareholder | 0 | 0 |
Capital expenditures | $ 0 | $ 0 |
Segment Information (Disaggrega
Segment Information (Disaggregation of Revenue) (Details) - USD ($) $ in Millions | 3 Months Ended | |
Mar. 31, 2019 | Mar. 31, 2018 | |
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | $ 1,556 | $ 1,585 |
Revenues from alternative revenue programs | 29 | 20 |
Other revenues not from contracts with customers | 9 | 25 |
Electricity | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 1,182 | 1,223 |
Electricity | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 529 | 551 |
Electricity | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 362 | 376 |
Electricity | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 89 | 96 |
Electricity | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 202 | 200 |
Natural Gas | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 374 | 362 |
Natural Gas | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 284 | 284 |
Natural Gas | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 81 | 83 |
Natural Gas | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 6 | 8 |
Natural Gas | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 3 | (13) |
Ameren Illinois Company | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 762 | 760 |
Ameren Illinois Company | Ameren Illinois Company | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 762 | 760 |
Revenues from alternative revenue programs | 14 | 24 |
Other revenues not from contracts with customers | 4 | 11 |
Ameren Illinois Company | Ameren Illinois Company | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 463 | 462 |
Ameren Illinois Company | Ameren Illinois Company | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 188 | 191 |
Ameren Illinois Company | Ameren Illinois Company | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 38 | 41 |
Ameren Illinois Company | Ameren Illinois Company | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 73 | 66 |
Ameren Illinois Company | Electricity | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 442 | 449 |
Ameren Illinois Company | Natural Gas | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 320 | 311 |
Operating Segments | Union Electric Company | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 758 | 792 |
Revenues from alternative revenue programs | 15 | (4) |
Other revenues not from contracts with customers | 5 | 14 |
Operating Segments | Ameren Illinois Electric Distribution | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 387 | 400 |
Revenues from alternative revenue programs | 22 | 31 |
Other revenues not from contracts with customers | 3 | 10 |
Operating Segments | Ameren Illinois Gas | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 320 | 311 |
Revenues from alternative revenue programs | (3) | (3) |
Other revenues not from contracts with customers | 1 | 1 |
Operating Segments | Ameren Transmission | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 114 | 104 |
Revenues from alternative revenue programs | (5) | (4) |
Other revenues not from contracts with customers | 0 | 0 |
Operating Segments | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Union Electric Company | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 704 | 741 |
Operating Segments | Electricity | Union Electric Company | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 312 | 332 |
Operating Segments | Electricity | Union Electric Company | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 239 | 252 |
Operating Segments | Electricity | Union Electric Company | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 55 | 61 |
Operating Segments | Electricity | Union Electric Company | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 98 | 96 |
Operating Segments | Electricity | Ameren Illinois Electric Distribution | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 387 | 400 |
Operating Segments | Electricity | Ameren Illinois Electric Distribution | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 217 | 219 |
Operating Segments | Electricity | Ameren Illinois Electric Distribution | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 123 | 124 |
Operating Segments | Electricity | Ameren Illinois Electric Distribution | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 34 | 35 |
Operating Segments | Electricity | Ameren Illinois Electric Distribution | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 13 | 22 |
Operating Segments | Electricity | Ameren Illinois Gas | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Ameren Illinois Gas | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Ameren Illinois Gas | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Ameren Illinois Gas | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Ameren Illinois Gas | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Ameren Transmission | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 114 | 104 |
Operating Segments | Electricity | Ameren Transmission | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Ameren Transmission | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Ameren Transmission | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Ameren Transmission | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 114 | 104 |
Operating Segments | Electricity | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Other | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Other | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Other | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Electricity | Other | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Union Electric Company | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 54 | 51 |
Operating Segments | Natural Gas | Union Electric Company | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 38 | 41 |
Operating Segments | Natural Gas | Union Electric Company | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 16 | 16 |
Operating Segments | Natural Gas | Union Electric Company | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 2 | 2 |
Operating Segments | Natural Gas | Union Electric Company | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | (2) | (8) |
Operating Segments | Natural Gas | Ameren Illinois Electric Distribution | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Ameren Illinois Electric Distribution | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Ameren Illinois Electric Distribution | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Ameren Illinois Electric Distribution | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Ameren Illinois Electric Distribution | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Ameren Illinois Gas | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 320 | 311 |
Operating Segments | Natural Gas | Ameren Illinois Gas | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 246 | 243 |
Operating Segments | Natural Gas | Ameren Illinois Gas | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 65 | 67 |
Operating Segments | Natural Gas | Ameren Illinois Gas | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 4 | 6 |
Operating Segments | Natural Gas | Ameren Illinois Gas | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 5 | (5) |
Operating Segments | Natural Gas | Ameren Transmission | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Ameren Transmission | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Ameren Transmission | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Ameren Transmission | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Ameren Transmission | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Other | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Other | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Other | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Natural Gas | Other | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Ameren Illinois Company | Ameren Illinois Electric Distribution | ||
Disaggregation of Revenue [Line Items] | ||
Revenues from alternative revenue programs | 22 | 31 |
Other revenues not from contracts with customers | 3 | 10 |
Operating Segments | Ameren Illinois Company | Ameren Illinois Gas | ||
Disaggregation of Revenue [Line Items] | ||
Revenues from alternative revenue programs | (3) | (3) |
Other revenues not from contracts with customers | 1 | 1 |
Operating Segments | Ameren Illinois Company | Ameren Illinois Transmission | ||
Disaggregation of Revenue [Line Items] | ||
Revenues from alternative revenue programs | (5) | (4) |
Other revenues not from contracts with customers | 0 | 0 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Electric Distribution | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 387 | 400 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Electric Distribution | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 217 | 219 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Electric Distribution | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 123 | 124 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Electric Distribution | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 34 | 35 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Electric Distribution | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 13 | 22 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Transmission | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 70 | 62 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Transmission | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Transmission | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Transmission | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Operating Segments | Ameren Illinois Company | Electricity | Ameren Illinois Transmission | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 70 | 62 |
Operating Segments | Ameren Illinois Company | Natural Gas | Ameren Illinois Gas | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 320 | 311 |
Operating Segments | Ameren Illinois Company | Natural Gas | Ameren Illinois Gas | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 246 | 243 |
Operating Segments | Ameren Illinois Company | Natural Gas | Ameren Illinois Gas | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 65 | 67 |
Operating Segments | Ameren Illinois Company | Natural Gas | Ameren Illinois Gas | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 4 | 6 |
Operating Segments | Ameren Illinois Company | Natural Gas | Ameren Illinois Gas | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 5 | (5) |
Intersegment Eliminations | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | (23) | (22) |
Intersegment Eliminations | Electricity | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | (23) | (22) |
Intersegment Eliminations | Electricity | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Electricity | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Electricity | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Electricity | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | (23) | (22) |
Intersegment Eliminations | Natural Gas | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Natural Gas | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Natural Gas | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Natural Gas | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Natural Gas | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Ameren Illinois Company | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | (15) | (13) |
Intersegment Eliminations | Ameren Illinois Company | Residential | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Ameren Illinois Company | Commercial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Ameren Illinois Company | Industrial | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | 0 | 0 |
Intersegment Eliminations | Ameren Illinois Company | Other | ||
Disaggregation of Revenue [Line Items] | ||
Revenue from Contract with Customer, Including Assessed Tax | $ (15) | $ (13) |