Amount of megawatts

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- Definition

Frequency of Integrated Resource Plan Filings

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- Definition

The MoPSC Staff's recommended rate increase (decrease).

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- Definition

The MoPSC Staff's recommended capital structure

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- Definition

The MoPSC Staff's recommended return on equity.

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The MoPSC Staff's recommended rate base.

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- Definition

Months to complete a rate proceeding

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

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- Definition

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

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Rate And Regulatory Matters [Line Items]

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- Definition

Value established for a utility on which the entity is allowed to earn a particular rate of return

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- 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.

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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

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

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

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- Definition

Percentage of public utility's requested equity to capital, including debt and equity.

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Amount of public utility's requested rate increase (decrease) with regulatory agency.

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Percentage of public utility's requested return on equity.

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- Definition

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

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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
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Rate And Regulatory Matters (Narrative-Missouri) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2027	Dec. 31, 2025	Jun. 30, 2025 USD ($)	Mar. 31, 2025 USD ($)	Jun. 30, 2024 MWh	Mar. 31, 2024 USD ($)	Sep. 30, 2023 MWh	Dec. 31, 2022 MWh
Rate And Regulatory Matters [Line Items]
Depreciation and amortization				$ 367		$ 361
Capital expenditures				$ 1,064		890
Union Electric Company
Rate And Regulatory Matters [Line Items]
PISA Deferral Percentage				85.00%
Depreciation and amortization				$ 194		195
Capital expenditures				$ 658		$ 466
Union Electric Company \| Maximum
Rate And Regulatory Matters [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Percentage				2.50%
Union Electric Company \| Maximum \| Subsequent Event
Rate And Regulatory Matters [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Percentage		2.25%
Union Electric Company \| Generation Facilities
Rate And Regulatory Matters [Line Items]
Capital expenditures				$ 1,700
Union Electric Company \| Electric \| Subsequent Event
Rate And Regulatory Matters [Line Items]
Frequency of Integrated Resource Plan Filings	4 years
Union Electric Company \| Electric \| Final Rate Order \| Subsequent Event
Rate And Regulatory Matters [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount			$ 355
Depreciation and amortization			70
Union Electric Company \| Build-transfer \| Solar generation facility
Rate And Regulatory Matters [Line Items]
Amount of Megawatts \| MWh							300
Union Electric Company \| Self-build \| Solar generation facility
Rate And Regulatory Matters [Line Items]
Amount of Megawatts \| MWh							50	50
Union Electric Company \| Self-build \| Natural Gas Generation Facility
Rate And Regulatory Matters [Line Items]
Amount of Megawatts \| MWh					800
Union Electric Company \| Natural gas \| Subsequent Event
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 \| Pending Rate Case
Rate And Regulatory Matters [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount				$ 38
Public Utilities, Requested Return on Equity, Percentage				10.25%
Public Utilities, Requested Equity Capital Structure, Percentage				52.00%
Rate Base				$ 525
Months to complete a rate proceeding				11 months
Union Electric Company \| Natural gas \| Pending Rate Case \| Subsequent Event
Rate And Regulatory Matters [Line Items]
MoPSC Staff recommended rate increase (decrease)			$ 32
MoPSC Staff's recommended ROE			9.64%
MoPSC Staff's recommended capital structure			52.00%
MoPSC Staff's recommended rate base			$ 482