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Discontinued Operations and Assets and Liabilities Held For Sale (Tables) | 12 Months Ended
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Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |
Components Of Discontinued Operations In Consolidated Statements Of Income | A summary of the components of discontinued operations in Alliant Energy’s income statements was as follows (in millions):
| 2014 |  | 2013 |  | 2012
Operating revenues |  | $— |  |  |  | $0.9 |  |  |  | $289.2 |
Operating expenses | 3.7 |  |  | 9.9 |  |  | 297.0 |
Interest expense and other | — |  |  | — |  |  | 0.7 |
Loss before income taxes | (3.7 | ) |  | (9.0 | ) |  | (8.5 | )
Income tax benefit | (1.3 | ) |  | (3.1 | ) |  | (3.4 | )
Loss from discontinued operations, net of tax |  | ($2.4 | ) |  |  | ($5.9 | ) |  |  | ($5.1 | )
Assets and Liabilities Held For Sale on Consolidated Balance Sheets | As of December 31, 2014, Alliant Energy’s and IPL’s balance sheets included assets held for sale recorded in “Other current assets” and liabilities held for sale recorded in “Other current liabilities” as follows (in millions):
Assets held for sale: |
Current assets |  | $1.1 |
Property, plant and equipment, net | 11.0 |
Other assets | 7.0 |
Total assets held for sale | 19.1 |
Liabilities held for sale: |
Current liabilities | 1.0 |
Other liabilities | 7.1 |
Total liabilities held for sale | 8.1 |
Net assets held for sale |  | $11.0 |
IPL [Member] |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |
Assets and Liabilities Held For Sale on Consolidated Balance Sheets | As of December 31, 2014, Alliant Energy’s and IPL’s balance sheets included assets held for sale recorded in “Other current assets” and liabilities held for sale recorded in “Other current liabilities” as follows (in millions):
Assets held for sale: |
Current assets |  | $1.1 |
Property, plant and equipment, net | 11.0 |
Other assets | 7.0 |
Total assets held for sale | 19.1 |
Liabilities held for sale: |
Current liabilities | 1.0 |
Other liabilities | 7.1 |
Total liabilities held for sale | 8.1 |
Net assets held for sale |  | $11.0 |

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- Definition Tabular disclosure of disposal groups, which may include the gain (loss) recognized in the income statement and the income statement caption that includes that gain (loss), amounts of revenues and pretax profit or loss reported in discontinued operations, the classification and carrying value of the assets and liabilities comprising the disposal group, and the segment in which the disposal group was reported. Also may include the amount of adjustments to amounts previously reported in discontinued operations such as resolution of contingencies arising from the disposal transaction or the operations of the component prior to disposal. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1361-107760 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6892542&loc=d3e957-107759 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1510-107760 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1474-107760 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2443-110228 + Details
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