Rate and Regulatory Matters (Regulatory Framework-Missouri) (Details) - Ameren Missouri	12 Months Ended
	Dec. 31, 2024 MWh
Public Utilities, General Disclosures [Line Items]
Number of months to complete a regulatory rate review	11 months
PISA deferral percentage	85.00%
Depreciation percentage not included in PISA deferral	15.00%
Amount of Megawatts	102
Sharing Level For Fac	95.00%
Percentage of variance not covered by FAC	5.00%
Base rate reset period	4 years
Maximum
Public Utilities, General Disclosures [Line Items]
Public utilities, approved rate increase (decrease), percentage	2.50%
PISA
Public Utilities, General Disclosures [Line Items]
Regulatory asset, amortization period	20 years