Rate and Regulatory Matters (Regulatory Framework-Illinois) (Details) - Ameren Illinois	12 Months Ended
Dec. 31, 2023 numberOfProposedPerformanceMetrics
IEIMA revenue requirement reconciliation adjustment
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Return on Equity, Percentage	5.80%
Regulatory asset, amortization period	2 years
FEJA
Public Utilities, General Disclosures [Line Items]
Public Utilities, Approved Return on Equity, Percentage	5.80%
Return on equity adjustment	2.00%
QIP rider
Public Utilities, General Disclosures [Line Items]
QIP recovery begin date	2 months
QIP rider reset	zero
Electric Distribution
Public Utilities, General Disclosures [Line Items]
MYRP return on equity adjustment	0.24%
Number of performance metrics	7
Electric Distribution \| IEIMA revenue requirement reconciliation adjustment
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period	2 years
Electric Distribution \| FEJA
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period	2 years
Natural gas
Public Utilities, General Disclosures [Line Items]
Number of months to complete a regulatory rate review	11 months
Maximum
Public Utilities, General Disclosures [Line Items]
Public utilities, approved rate increase (decrease), percentage	105.00%
Maximum \| QIP rider
Public Utilities, General Disclosures [Line Items]
Public utilities, approved rate increase (decrease), percentage	4.00%
Annual QIP rate cap	5.50%

Maximum annual increase in rates resulting from the QIP rider.

No definition available.

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- Definition

Potential return on equity adjustment under an MYRP.

+ References

No definition available.

+ Details

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- Definition

Number of Performance Metrics

+ References

No definition available.

+ Details

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- Definition

The number of months it takes to complete a regulatory rate review.

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
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- Definition

Recovery of the QIP regulatory asset begins two months after the qualifying natural gas plant is placed in service.

+ References

No definition available.

+ Details

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- Definition

When QIP rate base is transferred to base rates upon the issuance of a natural gas delivery service rate order, the QIP rider is reset to zero.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Return on equity adjustment related to the achievement of annual energy efficiency goals.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Percentage of public utility's approved return on equity.

+ References

No definition available.

+ Details

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- 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

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- Definition

Amortization period for the recovery of regulatory asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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