Name:	aee_DefinedBenefitPlanEffectOfQuarterPercentagePointDecreaseOfDiscountRateOnProjectedBenefitObligation
Namespace Prefix:	aee_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Defined Benefit Plan Effect Of a Quarter-Percentage Point Decrease of the Discount Rate On the Service And Interest Cost Components.

No definition available.

Name:	aee_DefinedBenefitPlanEffectOfQuarterPercentagePointDecreaseOfDiscountRateOnServiceAndInterestCostComponents
Namespace Prefix:	aee_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Defined Benefit Plan Effect Of a Quarter-Percentage Point Increase of the assumed annual salary increase Rate On the Projected Benefit Obligation.

No definition available.

Name:	aee_DefinedBenefitPlanEffectOfQuarterPercentagePointIncreaseOfAssumedAnnualSalaryIncreaseRateOnProjectedBenefitObligation
Namespace Prefix:	aee_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Defined Benefit Plan Effect Of a Quarter-Percentage Point Increase of the assumed annual salary increase Rate On the Service And Interest Cost Components.

No definition available.

Name:	aee_DefinedBenefitPlanEffectOfQuarterPercentagePointIncreaseOfAssumedAnnualSalaryIncreaseRateOnServiceAndInterestCostComponents
Namespace Prefix:	aee_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (m)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

Name:	us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

Name:	us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.