XML 164 R84.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Retirement Benefits (Assumptions Used To Determine Benefit Obligations) (Details) | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Pension Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Discount rate at measurement date | 5.25% | 5.55% |
Increase in future compensation | 3.50% | 3.50% |
Cash balance pension plan interest crediting rate | 5.50% | 5.00% |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase for 2023 |  | 4.50% |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase for 2024 | 4.00% | 4.00% |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate for 2023 |  | 5.50% |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate for 2024 |  | 5.50% |
Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Discount rate at measurement date | 5.25% | 5.55% |
Increase in future compensation | 3.50% | 3.50% |
Medical cost trend rate (initial) |  | 5.00% | 5.00%
Medical cost trend rate (ultimate) | 5.00% | 5.00% | 5.00%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase for 2023 |  | 4.50% |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase for 2024 | 4.00% | 4.00% |
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year, Pre-Medicare Plan Participantes | 6.93% | 7.25% |
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year, Post-Medicare Plan Participants | 6.50% | 6.75% |
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate | 2030 |  |
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year, Post-Medicare Plan Participants Adjustment | 3.00% |  |
Postretirement Health Coverage |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Medical cost trend rate (initial) | 2.50% | 2.50% |
Medical cost trend rate (ultimate) | 2.50% | 3.00% | 3.00%

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase for 2023 + References No definition available. + Details
Name: | aee_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncreaseFor2023
Namespace Prefix: | aee_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase for 2024 + References No definition available. + Details
Name: | aee_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncreaseFor2024
Namespace Prefix: | aee_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate for 2023 + References No definition available. + Details
Name: | aee_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRateFor2023
Namespace Prefix: | aee_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate for 2024 + References No definition available. + Details
Name: | aee_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRateFor2024
Namespace Prefix: | aee_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year, Post-Medicare Plan Participants + References No definition available. + Details
Name: | aee_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYearPostMedicarePlanParticipants
Namespace Prefix: | aee_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year, Post-Medicare Plan Participants Adjustment + References No definition available. + Details
Name: | aee_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYearPostMedicarePlanParticipantsAdjustment
Namespace Prefix: | aee_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year, Pre-Medicare Plan Participants + References No definition available. + Details
Name: | aee_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYearPreMedicarePlanParticipants
Namespace Prefix: | aee_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (k)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (k)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted-average interest crediting rate used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, cash balance and other defined benefit plans with promised interest crediting rate. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (k)(4) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Assumed rate, for next fiscal year, based on annual change in cost of health care cost benefits used to measure expected cost of benefits covered by defined benefit postretirement plan. Factors include, but are not limited to, estimate of health care inflation, change in health care utilization or delivery pattern, technological advances, and change in health status of participant. Excludes factors for change in composition of plan population by age and dependency status. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (l) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Ultimate trend rate for health care cost for defined benefit postretirement plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (l) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Year ultimate health care cost trend rate is expected to be reached, in YYYY format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (l) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:gYearListItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_DefinedBenefitPostretirementHealthCoverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |