XML 77 R48.htm IDEA: XBRL DOCUMENT
v3.25.1

Derivative Financial Instruments (Derivative Instruments Carrying Value) (Detail) - Not Designated As Hedging Instrument - USD ($) $ in Millions | Mar. 31, 2025 | Dec. 31, 2024
--- | --- | ---
Derivative [Line Items] |  |
Derivative Assets | $ 27 | $ 16
Derivative Liability | 99 | 103
Fuel oils | Other current liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 2 | 2
Fuel oils | Other deferred credits and liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 1 | 2
Natural gas | Other current assets |  |
Derivative [Line Items] |  |
Derivative Assets | 15 | 4
Natural gas | Other assets |  |
Derivative [Line Items] |  |
Derivative Assets | 7 | 6
Natural gas | Other current liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 8 | 27
Natural gas | Other deferred credits and liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 21 | 19
Power | Other current assets |  |
Derivative [Line Items] |  |
Derivative Assets | 5 | 6
Power | Other current liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 7 | 10
Power | Other deferred credits and liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 60 | 43
Union Electric Company |  |
Derivative [Line Items] |  |
Derivative Assets | 11 | 10
Derivative Liability | 12 | 15
Union Electric Company | Fuel oils | Other current liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 2 | 2
Union Electric Company | Fuel oils | Other deferred credits and liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 1 | 2
Union Electric Company | Natural gas | Other current assets |  |
Derivative [Line Items] |  |
Derivative Assets | 4 | 2
Union Electric Company | Natural gas | Other assets |  |
Derivative [Line Items] |  |
Derivative Assets | 2 | 2
Union Electric Company | Natural gas | Other current liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 2 | 5
Union Electric Company | Natural gas | Other deferred credits and liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 7 | 6
Union Electric Company | Power | Other current assets |  |
Derivative [Line Items] |  |
Derivative Assets | 5 | 6
Union Electric Company | Power | Other current liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 0 | 0
Union Electric Company | Power | Other deferred credits and liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 0 | 0
Ameren Illinois Company |  |
Derivative [Line Items] |  |
Derivative Assets | 16 | 6
Derivative Liability | 87 | 88
Ameren Illinois Company | Fuel oils | Other current liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 0 | 0
Ameren Illinois Company | Fuel oils | Other deferred credits and liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 0 | 0
Ameren Illinois Company | Natural gas | Other current assets |  |
Derivative [Line Items] |  |
Derivative Assets | 11 | 2
Ameren Illinois Company | Natural gas | Other assets |  |
Derivative [Line Items] |  |
Derivative Assets | 5 | 4
Ameren Illinois Company | Natural gas | Other current liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 6 | 22
Ameren Illinois Company | Natural gas | Other deferred credits and liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 14 | 13
Ameren Illinois Company | Power | Other current assets |  |
Derivative [Line Items] |  |
Derivative Assets | 0 | 0
Ameren Illinois Company | Power | Other current liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | 7 | 10
Ameren Illinois Company | Power | Other deferred credits and liabilities |  |
Derivative [Line Items] |  |
Derivative Liability | $ 60 | $ 43

X
- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-22 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483466/210-20-50-3 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-7 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (c)(2) -SubTopic 20 -Topic 860 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481326/860-20-50-4D + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-22 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483466/210-20-50-3 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-7 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (c)(2) -SubTopic 20 -Topic 860 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481326/860-20-50-4D + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480237/815-40-50-5 + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TradingActivityByTypeAxis=aee_FuelOilsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherCurrentLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TradingActivityByTypeAxis=srt_NaturalGasReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherCurrentAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TradingActivityByTypeAxis=aee_PowerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=aee_UnionElectricCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=aee_AmerenIllinoisCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |