Collateralized loan percentage compared to asset's market value

No definition available.

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- Definition

The change in the interest rate used to adjust for the time value of money for the plan

+ References

No definition available.

+ Details

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- Definition

The employer's best estimate, as soon as it can be reasonably determined, of the contributions expected to be paid to the plan during the next five fiscal years beginning after the date of the latest statement of financial position. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions.

+ References

No definition available.

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- Definition

Defined Benefit Plan, Future Funding Requirement, Percentage

+ References

No definition available.

+ Details

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- Definition

Defined Benefit Plan Number of High Quality Bonds Used to Determine Yield Curve

+ References

No definition available.

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- Definition

Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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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.

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- Definition

Amount of funded (unfunded) status of defined benefit plan, measured as difference between fair value of plan assets and benefit obligation. Includes, but is not limited to, overfunded (underfunded) status.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition

Amount, after the effects of master netting arrangements, of securities loaned to entities in exchange for collateral. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 30
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Retirement Benefits (Narrative) (Details) $ in Millions	12 Months Ended
Retirement Benefits (Narrative) (Details) $ in Millions	Dec. 31, 2025	Dec. 31, 2024 USD ($) bond	Dec. 31, 2023 USD ($)	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan		$ 734	$ 551
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation, Change in Discount Rate		0.45%
Number of high-quality corporate bonds \| bond		860
Defined benefit plan estimated future employer contributions over next five years		$ 170
Collateralized loan percentage compared to asset's market value		102.00%
Securities Loaned		$ 454	234
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Funded (Unfunded) Status of Plan		$ 48	$ 14
Expected return on plan assets		6.75%	6.75%	6.50%
Pension Benefits \| Forecast
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	6.75%
Ameren Missouri \| Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Future funding requirement, percentage		40.00%
Ameren Illinois \| Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Future funding requirement, percentage		50.00%