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Preferred Stock (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Temporary Equity [Line Items] |  |  |
Payments to redeem cumulative preferred stock of IPL | $ 200 | $ 0 | $ 0
Cumulative Preferred Stock [Member] | 5.1% [Member] |  |  |
Temporary Equity [Line Items] |  |  |
Non-cash charge, preferred stock redemption | 5 |  |
IPL [Member] |  |  |
Temporary Equity [Line Items] |  |  |
Payments to redeem cumulative preferred stock of IPL | $ 200 | $ 0 | $ 0
IPL [Member] | Cumulative Preferred Stock [Member] |  |  |
Temporary Equity [Line Items] |  |  |
Shares authorized (in shares) | 16,000,000 |  |
IPL [Member] | Cumulative Preferred Stock [Member] | 5.1% [Member] |  |  |
Temporary Equity [Line Items] |  |  |
Shares authorized (in shares) |  | 8,000,000 |
Shares outstanding (in shares) |  | 8,000,000 |
Cumulative preferred stock rate |  | 5.10% |
Preferred stock redemption price per share (in dollars per share) |  | $ 25 |
Payments to redeem cumulative preferred stock of IPL | $ 200 |  |
Non-cash charge, preferred stock redemption | $ 5 |  |

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- Definition Amount of preferred stock dividends and adjustments classified as other. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=125511455&loc=d3e1377-109256 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 7 -Subparagraph (SAB Topic 5.Q) -URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187283-122770 + Details
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- Definition The cash outflow for reacquisition of callable preferred stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585 + Details
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- Definition The percentage rate used to calculate dividend payments on preferred stock. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644 + Details
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- Definition The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21488-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21475-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21564-112644 + Details
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