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Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2019 | Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Increase in operating cash flows from change in method of presentation to daily transactional activity |  | $ 67.0
Net cash flows from operating activities | $ 181.1 | 156.3
IPL [Member] |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Increase in operating cash flows from change in method of presentation to daily transactional activity |  | 67.0
Net cash flows from operating activities | $ 76.7 | $ 1.8

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- Definition Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3536-108585 + Details
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