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Commitments And Contingencies (Operating Expense Purchase Obligations) (Details) $ in Millions | 6 Months Ended
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Jun. 30, 2016 USD ($)
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | $ 2,175 |
Individual commitments incurred | 1 |
IPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 1,698 |
Individual commitments incurred | 1 |
WPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 462 |
Individual commitments incurred | 1 |
DAEC (IPL) [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 1,356 | [1]
DAEC (IPL) [Member] | IPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 1,356 | [1]
DAEC (IPL) [Member] | WPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 0 | [1]
Other [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 158 | [1]
Other [Member] | IPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 1 | [1]
Other [Member] | WPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 157 | [1]
Purchased Power [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 1,514 | [1]
Purchased Power [Member] | IPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 1,357 | [1]
Purchased Power [Member] | WPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 157 | [1]
Natural Gas [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 416 |
Natural Gas [Member] | IPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 239 |
Natural Gas [Member] | WPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 177 |
Coal [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 212 | [2]
Coal [Member] | IPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 86 | [2]
Coal [Member] | WPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 126 | [2]
SO2 emission allowances [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 8 |
SO2 emission allowances [Member] | IPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 8 |
SO2 emission allowances [Member] | WPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 0 |
Other [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 25 | [3]
Other [Member] | IPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | 8 | [3]
Other [Member] | WPL [Member] |  |
Commitments and Contingencies [Line Items] |  |
Minimum future commitments | $ 2 | [3]
[1] | Includes payments required by purchased power agreements for capacity rights and minimum quantities of MWhs required to be purchased.
[2] | Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of June 30, 2016 regarding expected future usage, which is subject to change.
[3] | Includes individual commitments incurred during the normal course of business that exceeded $1 million at June 30, 2016.

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- Definition Individual commitments incurred in excess of $1 million + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition The minimum amount the entity agreed to spend under the long-term purchase commitment. + References No definition available. + Details
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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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- Details
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Namespace Prefix: |
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Balance Type: |
Period Type: |

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- Details
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- Details
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- Details
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- Details
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- Details
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Balance Type: |
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
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- Details
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