v2.4.0.6

Commitments And Contingencies (Schedule Of Environmental Liabilities) (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2012 | Dec. 31, 2011
--- | --- | ---
Current environmental liabilities | $ 3.7 | $ 4.8
Non-current environmental liabilities | 25.3 | 28.8
Total environmental liabilities | 29.0 | 33.6
IPL [Member] |  |
Current environmental liabilities | 2.5 | 3.5
Non-current environmental liabilities | 23.2 | 24.9
Total environmental liabilities | 25.7 | 28.4
WPL [Member] |  |
Current environmental liabilities | 1.2 | 1.3
Non-current environmental liabilities | 2.1 | 3.8
Total environmental liabilities | $ 3.3 | $ 5.1

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