Redeemable Preferred Stock (Carrying Value Of Cumulative Preferred Stock) (Details) - IPL [Member] - Redeemable Preferred Stock [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Temporary Equity [Line Items]
Shares Authorized (in shares)	16,000,000
5.1% [Member]
Temporary Equity [Line Items]
Series	5.10%	5.10%
Liquidation Preference/Stated Value (in dollars per share)	$ 25	$ 25
Shares Authorized (in shares)	8,000,000	8,000,000
Shares Outstanding (in shares)	8,000,000	8,000,000
Cumulative preferred stock	$ 200.0	$ 200.0

The percentage rate used to calculate dividend payments on preferred stock.

No definition available.

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- Definition

Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

+ References

+ Details

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- Definition

Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

+ References

+ Details

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- Definition

Aggregate par or stated value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity.

+ References

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- 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

No definition available.

+ Details

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