| Cover | Dec. 20, 2024 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Dec. 20, 2024 |
| Entity File Number | 333-282616 |
| Entity Registrant Name | Union Electric Company |
| Entity Central Index Key | 0000100826 |
| Entity Tax Identification Number | 43-0559760 |
| Entity Incorporation, State or Country Code | MO |
| Entity Address, Address Line One | 1901 Chouteau Avenue |
| Entity Address, City or Town | St. Louis |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 63103 |
| City Area Code | 314 |
| Local Phone Number | 621-3222 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Ameren Missouri Securitization Funding Illc [Member] | |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Dec. 20, 2024 |
| Entity File Number | 333-282616-01 |
| Entity Registrant Name | Ameren Missouri Securitization Funding I, LLC |
| Entity Central Index Key | 0002039835 |
| Entity Tax Identification Number | 33-1368847 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 1901 Chouteau Avenue |
| Entity Address, City or Town | St. Louis |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 63103 |
| City Area Code | 314 |
| Local Phone Number | 621-3222 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
