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Commitments And Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified | 6 Months Ended
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Jun. 30, 2014
Long-term Purchase Commitment [Line Items] |
Minimum future commitments | $ 2,423
Performance guarantees outstanding | 313
Present value abandonment obligation | 31
IPL [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments | 1,902
Number of sites monitoring and remediating (in sites) | 27
WPL [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments | 518
Number of sites monitoring and remediating (in sites) | 5
Capital Purchase Obligation [Member] | Alliant Energy and IPL [Member] |
Long-term Purchase Commitment [Line Items] |
Minimum future commitments | 59
Indemnification Agreement [Member] | RMT [Member] |
Long-term Purchase Commitment [Line Items] |
Loss contingency, estimate of possible loss | 3
Performance guarantees outstanding, 2014 [Member] |
Long-term Purchase Commitment [Line Items] |
Performance guarantees outstanding | 137
Performance guarantees outstanding, 2015 [Member] |
Long-term Purchase Commitment [Line Items] |
Performance guarantees outstanding | 53
Performance guarantees outstanding, 2016 [Member] |
Long-term Purchase Commitment [Line Items] |
Performance guarantees outstanding | 123
Environmental Issue [Member] | WPL [Member] |
Long-term Purchase Commitment [Line Items] |
Loss contingency, damages awarded, value | $ 7
Minimum [Member] |
Long-term Purchase Commitment [Line Items] |
Warranty period | 12 months
Maximum [Member] |
Long-term Purchase Commitment [Line Items] |
Warranty period | 60 months

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- Definition Number of sites remediating and monitoring + References No definition available. + Details
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- Definition Performance Guarantees Outstanding + References No definition available. + Details
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- Definition Present value abandonment obligation + References No definition available. + Details
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- Definition Warranty Period + References No definition available. + Details
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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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- Details
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- Definition Amount of damages awarded to the plaintiff in the legal matter. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349 + Details
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- Definition Reflects the estimated amount of loss from the specified contingency as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 9 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349 + Details
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