XML 71 R38.htm IDEA: XBRL DOCUMENT v3.25.3

Rate And Regulatory Matters (Narrative-Missouri) (Details) $ in Millions	3 Months Ended							9 Months Ended
	Sep. 30, 2025 USD ($) MWh	Jun. 30, 2025 MWh	Mar. 31, 2025	Sep. 30, 2024 USD ($)	Jun. 30, 2024 MWh	Jun. 30, 2023 MWh	Mar. 31, 2023 MWh	Sep. 30, 2025 USD ($) MWh	Sep. 30, 2024 USD ($)
Rate And Regulatory Matters [Line Items]
Depreciation and amortization	$ 415			$ 388				$ 1,168	$ 1,125
Capital expenditures								$ 3,118	3,029
Union Electric Company
Rate And Regulatory Matters [Line Items]
PISA Deferral Percentage								85.00%
Depreciation and amortization	$ 239			$ 220				$ 642	623
Capital expenditures								1,873	$ 1,839
Union Electric Company | Maximum
Rate And Regulatory Matters [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Percentage	2.25%		2.50%
Union Electric Company | Natural Gas Generation Facility
Rate And Regulatory Matters [Line Items]
Capital expenditures								900
Union Electric Company | Solar Generation Facilities
Rate And Regulatory Matters [Line Items]
Capital expenditures								$ 800
Union Electric Company | Electric
Rate And Regulatory Matters [Line Items]
Senate Bill 4 large service tariff threshold MWs | MWh								100
Frequency of Integrated Resource Plan Filings								4 years
Large load customer rate plan megawatts requested | MWh								75
Minimum service term for large load customer rate plan								12 years
Optional ramp up period for large load customer rate plan								5 years
Minimum demand charges as percentage of contracted capacity for large load customer rate plan								80.00%
Union Electric Company | Electric | Final Rate Order
Rate And Regulatory Matters [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount								$ 355
Depreciation and amortization								$ 70
Union Electric Company | Natural gas
Rate And Regulatory Matters [Line Items]
Number of days after end of test year to perform reconciliation when using a future test year								45 days
Union Electric Company | Natural gas | Final Rate Order
Rate And Regulatory Matters [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount								$ 32
Union Electric Company | Self-build | Solar generation facility
Rate And Regulatory Matters [Line Items]
Amount of Megawatts | MWh	250					50	50
Union Electric Company | Self-build | Natural Gas Generation Facility
Rate And Regulatory Matters [Line Items]
Amount of Megawatts | MWh		800			800
Union Electric Company | Self-build | Energy Storage Facility
Rate And Regulatory Matters [Line Items]
Amount of Megawatts | MWh		400
Union Electric Company | Build-transfer | Solar generation facility
Rate And Regulatory Matters [Line Items]
Amount of Megawatts | MWh						300

X

- Definition

Amount of megawatts

+ References

No definition available.

+ Details

Name:	aee_AmountofMegawatts
Namespace Prefix:	aee_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Frequency of Integrated Resource Plan Filings

+ References

No definition available.

+ Details

Name:	aee_FrequencyOfIntegratedResourcePlanFilings
Namespace Prefix:	aee_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Large load customer rate plan megawatts requested

+ References

No definition available.

+ Details

Name:	aee_LargeLoadCustomerRatePlanMegawattsRequested
Namespace Prefix:	aee_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Minimum demand charges as percentage of contracted capacity for large load customer rate plan

+ References

No definition available.

+ Details

Name:	aee_MinimumDemandChargesAsPercentageOfContractedCapacityForLargeLoadCustomerRatePlan
Namespace Prefix:	aee_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Minimum service term for large load customer rate plan

+ References

No definition available.

+ Details

Name:	aee_MinimumServiceTermForLargeLoadCustomerRatePlan
Namespace Prefix:	aee_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of days after end of test year to perform reconciliation when using a future test year

+ References

No definition available.

+ Details

Name:	aee_NumberOfDaysAfterEndOfTestYearToPerformReconciliationWhenUsingAFutureTestYear
Namespace Prefix:	aee_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Optional ramp up period for large load customer rate plan

+ References

No definition available.

+ Details

Name:	aee_OptionalRampUpPeriodForLargeLoadCustomerRatePlan
Namespace Prefix:	aee_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Deferral percentage of the depreciation expense on certain property, plant, and equipment placed in-service and not included in base rates.

+ References

No definition available.

+ Details

Name:	aee_PISADeferralPercentage
Namespace Prefix:	aee_
Data Type:	dtr-types:percentItemType
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

Senate Bill 4 large service tariff megawatt threshold

+ References

No definition available.

+ Details

Name:	aee_SenateBill4LargeServiceTariffThresholdMWs
Namespace Prefix:	aee_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 13
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-13

+ Details

Name:	us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of public utility's approved rate increase (decrease) by regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Percentage of public utility's approved rate increase (decrease) by regulatory agency.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesApprovedRateIncreaseDecreasePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of operating expense for depreciation and amortization of regulated operation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(2)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

+ Details

Name:	us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	dei_LegalEntityAxis=aee_UnionElectricCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=aee_NaturalGasGenerationFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=aee_SolarGenerationFacilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PublicUtilityAxis=us-gaap_ElectricityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=aee_FinalRateOrderMember
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:

X

- Details

Name:	us-gaap_PublicUtilityAxis=aee_SelfBuildMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=aee_SolarGenerationFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=aee_EnergyStorageFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PublicUtilityAxis=aee_BuildTransferMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: