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Commitments And Contingencies (Schedule Of Environmental Liabilities) (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2015 | Dec. 31, 2014
Current environmental liabilities | $ 2.7 | $ 2.0
Non-current environmental liabilities | 12.8 | 13.5
Total environmental liabilities | 15.5 | 15.5
Minimum range of estimated future cost incurred for investigation, remediation and monitoring | 11.0 |
Maximum remaining estimated cost incurred for investigation, remediation and monitoring | 28.0 |
IPL [Member] |  |
Current environmental liabilities | 1.7 | 1.7
Non-current environmental liabilities | 11.2 | 11.9
Total environmental liabilities | 12.9 | 13.6
Minimum range of estimated future cost incurred for investigation, remediation and monitoring | 9.0 |
Maximum remaining estimated cost incurred for investigation, remediation and monitoring | 25.0 |
WPL [Member] |  |
Current environmental liabilities | 1.0 | 0.3
Non-current environmental liabilities | 1.5 | 1.6
Total environmental liabilities | 2.5 | $ 1.9
Minimum range of estimated future cost incurred for investigation, remediation and monitoring | 2.0 |
Maximum remaining estimated cost incurred for investigation, remediation and monitoring | 3.0 |
Manufactured Gas Plant [Member] |  |
Total environmental liabilities | 15.0 |
Manufactured Gas Plant [Member] | IPL [Member] |  |
Total environmental liabilities | 13.0 |
Manufactured Gas Plant [Member] | WPL [Member] |  |
Total environmental liabilities | $ 2.0 |

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