Administrative law judge's recommended rate increase

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- Definition

Annual investment in energy-efficiency programs.

+ References

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- Definition

ICC Staff's recommended capital structure

+ References

No definition available.

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- Definition

ICC Staff's recommended ROE

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No definition available.

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- Definition

ICC Staff's recommended rate base

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No definition available.

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- Definition

The rate increase recommended by the ICC staff.

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No definition available.

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- Definition

Illinois Attorney General's office's recommended capital structure

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No definition available.

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- Definition

Illinois Attorney General's office's recommended ROE

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No definition available.

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- Definition

Illinois Attorney General's office's recommended rate base

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No definition available.

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- Definition

Illinois Attorney General's office's recommended rate increase

+ References

No definition available.

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- Definition

Multi-year rate plan revenue requirement approved by the ICC.

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No definition available.

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- Definition

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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No definition available.

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- Definition

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

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No definition available.

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- Definition

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

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No definition available.

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- Definition

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

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No definition available.

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- Definition

Percentage of public utility's requested return on equity.

+ References

No definition available.

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Rate And Regulatory Matters (Narrative-Illinois) (Details) - Ameren Illinois Company - USD ($) $ in Millions	3 Months Ended	6 Months Ended				9 Months Ended
	Dec. 31, 2025	Jun. 30, 2028	Jun. 30, 2027	Jun. 30, 2026	Jun. 30, 2025	Sep. 30, 2025
Rate And Regulatory Matters [Line Items]
Annual investment in energy-efficiency programs						$ 126
IETL \| Electric Distribution
Rate And Regulatory Matters [Line Items]
Multi-year rate plan approved revenue requirement					$ 1,206
Public Utilities, Approved Rate Increase (Decrease), Amount					$ 308
IETL \| Electric Distribution \| Forecast
Rate And Regulatory Matters [Line Items]
Multi-year rate plan approved revenue requirement		$ 1,421	$ 1,367	$ 1,287
Pending Rate Case \| Electric Distribution
Rate And Regulatory Matters [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount						$ 60
Public Utilities, Requested Equity Capital Structure, Percentage						50.00%
ICC Staff's recommended rate base						$ 47
Pending Rate Case \| Electric Energy-Efficiency
Rate And Regulatory Matters [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount						12
Pending Rate Case \| Natural gas
Rate And Regulatory Matters [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount						$ 135
Public Utilities, Requested Equity Capital Structure, Percentage						52.00%
Public Utilities, Requested Return on Equity, Percentage						10.70%
Rate Base						$ 3,300
ICC staff recommended rate increase						$ 104
ICC recommended ROE						9.93%
ICC Staff's recommended capital structure						50.00%
ICC Staff's recommended rate base						$ 3,200
Illinois Attorney General's office's recommended rate increase						$ 55
Illinois Attorney General's office's recommended ROE						9.45%
Illinois Attorney General's office's recommended capital structure						50.00%
Illinois Attorney General's office's recommended rate base						$ 3,000
Pending Rate Case \| Natural gas \| Subsequent Event
Rate And Regulatory Matters [Line Items]
Administrative law judge's recommended rate increase	$ 91