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Commitments And Contingencies Commitments And Contingencies (MPG Site Estimated Future Costs And Recorded Liabilities) (Details) (Manufactured Gas Plant Sites [Member], USD $) In Millions, unless otherwise specified | 9 Months Ended
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Sep. 30, 2014
Commitments and Contingencies [Line Items] |
Minimum range of estimated future costs | $ 13
Maximum range of estimated future costs | 32
Current and non-current environmental liabilities | 19
IPL [Member] |
Commitments and Contingencies [Line Items] |
Minimum range of estimated future costs | 12
Maximum range of estimated future costs | 30
Current and non-current environmental liabilities | 17
WPL [Member] |
Commitments and Contingencies [Line Items] |
Minimum range of estimated future costs | 1
Maximum range of estimated future costs | 2
Current and non-current environmental liabilities | $ 2

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- Definition Maximum Remaining Estimated Cost Incurred for Investigation, Remediation and Monitoring + References No definition available. + Details
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- Definition Total costs accrued as of the balance sheet date for environmental loss contingencies. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 Reference 2: 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 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346 + Details
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