XML 68 R36.htm IDEA: XBRL DOCUMENT
v3.23.1

Rate And Regulatory Matters (Narrative-Illinois) (Details) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2023 USD ($) | Mar. 31, 2023 USD ($) numberOfProposedPerformanceMetrics | Mar. 31, 2022 USD ($) | Dec. 31, 2027 USD ($) | Dec. 31, 2026 USD ($) | Dec. 31, 2025 USD ($) | Dec. 31, 2024 USD ($)
Rate And Regulatory Matters [Line Items] |  |  |  |  |  |  |
Revenues |  | $ 2,062 | $ 1,879 |  |  |  |
Ameren Illinois Company |  |  |  |  |  |  |
Rate And Regulatory Matters [Line Items] |  |  |  |  |  |  |
Revenues |  | $ 1,101 | $ 1,024 |  |  |  |
Ameren Illinois Company | Electric Distribution |  |  |  |  |  |  |
Rate And Regulatory Matters [Line Items] |  |  |  |  |  |  |
Number of Performance Metrics | numberOfProposedPerformanceMetrics |  | 7 |  |  |  |  |
Requested Return on Equity Adjustment |  | 0.24% |  |  |  |  |
IETL | Ameren Illinois Company | Electric Distribution |  |  |  |  |  |  |
Rate And Regulatory Matters [Line Items] |  |  |  |  |  |  |
Public Utilities, Approved Equity Capital Structure, Percentage |  | 50.00% |  |  |  |  |
Amortization Period |  | 2 years |  |  |  |  |
Amortization Start Date |  | 1 year |  |  |  |  |
Multi-Year Rate Plan Reconciliation Cap |  | 105.00% |  |  |  |  |
IETL | Ameren Illinois Company | Electric Distribution | Subsequent Event |  |  |  |  |  |  |
Rate And Regulatory Matters [Line Items] |  |  |  |  |  |  |
Multi-year rate plan requested revenue requirement |  |  |  | $ 1,556 | $ 1,477 | $ 1,373 | $ 1,282
Public Utilities, Requested Return on Equity, Percentage |  |  |  | 10.50% | 10.50% | 10.50% | 10.50%
Public Utilities, Requested Equity Capital Structure, Percentage |  |  |  | 54.03% | 54.02% | 53.97% | 53.99%
Rate Base |  |  |  | $ 5,300 | $ 5,000 | $ 4,600 | $ 4,300
Public Utilities, Requested Rate Increase (Decrease), Percentage |  |  |  |  |  |  | 50.00%
Public Utilities, Requested Rate Increase (Decrease), Amount |  |  |  |  |  |  | $ 171
IETL | Ameren Illinois Company | Electric Distribution | Minimum |  |  |  |  |  |  |
Rate And Regulatory Matters [Line Items] |  |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Percentage |  | 50.00% |  |  |  |  |
Pending Rate Case | Ameren Illinois Company | Electric Distribution | Subsequent Event |  |  |  |  |  |  |
Rate And Regulatory Matters [Line Items] |  |  |  |  |  |  |
Public Utilities, Requested Equity Capital Structure, Percentage | 53.99% |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount | $ 127 |  |  |  |  |  |
Pending Rate Case | Ameren Illinois Company | Natural gas |  |  |  |  |  |  |
Rate And Regulatory Matters [Line Items] |  |  |  |  |  |  |
Public Utilities, Requested Return on Equity, Percentage |  | 10.70% |  |  |  |  |
Public Utilities, Requested Equity Capital Structure, Percentage |  | 53.99% |  |  |  |  |
Rate Base |  | $ 2,900 |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount |  | 160 |  |  |  |  |
Revenues |  | $ 77 |  |  |  |  |

X
- Definition Amortization period of a regulatory asset or liability + References No definition available. + Details
Name: | aee_AmortizationPeriod
Namespace Prefix: | aee_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The date amortization of a regulatory asset or liability begins. + References No definition available. + Details
Name: | aee_AmortizationStartDate
Namespace Prefix: | aee_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Multi-Year Rate Plan Reconciliation Cap + References No definition available. + Details
Name: | aee_MultiYearRatePlanReconciliationCap
Namespace Prefix: | aee_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ameren Illinois' requested multi-year rate plan revenue requirement. + References No definition available. + Details
Name: | aee_MultiYearRatePlanRequestedRevenueRequirement
Namespace Prefix: | aee_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Number of Performance Metrics + References No definition available. + Details
Name: | aee_NumberOfPerformanceMetrics
Namespace Prefix: | aee_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Rate And Regulatory Matters [Line Items] + References No definition available. + Details
Name: | aee_RateAndRegulatoryMattersLineItems
Namespace Prefix: | aee_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value established for a utility on which the entity is allowed to earn a particular rate of return + References No definition available. + Details
Name: | aee_RateBase
Namespace Prefix: | aee_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The return on equity adjustments related to the achievement of certain performance metrics requested by Ameren Illinois. + References No definition available. + Details
Name: | aee_RequestedReturnOnEquityAdjustment
Namespace Prefix: | aee_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's approved equity to capital, including debt and equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedEquityCapitalStructurePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's requested equity to capital, including debt and equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedEquityCapitalStructurePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of public utility's requested rate increase (decrease) with regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of public utility's requested rate increase (decrease) with regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedRateIncreaseDecreasePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's requested return on equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedReturnOnEquityPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9031-108599 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 235 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -URI http://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756 Reference 22: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)) -URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=aee_AmerenIllinoisCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=us-gaap_ElectricDistributionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=aee_IETLMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=aee_PendingRateCaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilityAxis=srt_NaturalGasReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |