v2.4.0.6

Derivative Instruments (Tables) | 12 Months Ended
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Dec. 31, 2012
Derivative [Line Items] |
Notional Amounts of Derivative Instruments | As of December 31, 2012, notional amounts by delivery year related to outstanding swap contracts, option contracts, physical forward contracts, FTRs and coal contracts that were accounted for as commodity derivative instruments were as follows (units in thousands):
| 2013 |  | 2014 |  | 2015 |  | Total
Alliant Energy |  |  |  |  |  |  |
Electricity (MWhs) | 4,130 |  |  | 2,670 |  |  | 876 |  |  | 7,676 |
FTRs (MWs) | 28 |  |  | — |  |  | — |  |  | 28 |
Natural gas (dekatherms (Dths)) | 72,105 |  |  | 7,747 |  |  | 450 |  |  | 80,302 |
Coal (tons) | 896 |  |  | 981 |  |  | 562 |  |  | 2,439 |
IPL |  |  |  |  |  |  |
Electricity (MWhs) | 2,209 |  |  | 549 |  |  | — |  |  | 2,758 |
FTRs (MWs) | 15 |  |  | — |  |  | — |  |  | 15 |
Natural gas (Dths) | 57,731 |  |  | 3,535 |  |  | 225 |  |  | 61,491 |
WPL |  |  |  |  |  |  |
Electricity (MWhs) | 1,921 |  |  | 2,121 |  |  | 876 |  |  | 4,918 |
FTRs (MWs) | 13 |  |  | — |  |  | — |  |  | 13 |
Natural gas (Dths) | 14,374 |  |  | 4,212 |  |  | 225 |  |  | 18,811 |
Coal (tons) | 896 |  |  | 981 |  |  | 562 |  |  | 2,439 |
Fair Value of Financial Instruments | At December 31, the fair values of current derivative assets were included in “Prepayments and other,” non-current derivative assets were included in “Deferred charges and other,” current derivative liabilities were included in “Derivative liabilities” and non-current derivative liabilities were included in “Other long-term liabilities and deferred credits” on the Consolidated Balance Sheets as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Commodity contracts | 2012 |  | 2011 |  | 2012 |  | 2011 |  | 2012 |  | 2011
Current derivative assets |  | $23.5 |  |  |  | $12.7 |  |  |  | $17.0 |  |  |  | $9.2 |  |  |  | $6.5 |  |  |  | $3.5 |
Non-current derivative assets | 2.7 |  |  | 3.0 |  |  | 0.5 |  |  | 1.4 |  |  | 2.2 |  |  | 1.6 |
Current derivative liabilities | 31.1 |  |  | 55.9 |  |  | 14.1 |  |  | 24.5 |  |  | 17.0 |  |  | 31.4 |
Non-current derivative liabilities | 9.3 |  |  | 22.1 |  |  | 2.0 |  |  | 9.1 |  |  | 7.3 |  |  | 13.0 |
Gains and Losses from Derivative Instruments Not Designated as Hedging Instruments | Changes in unrealized gains (losses) from derivative instruments not designated as hedging instruments were recorded with offsets to regulatory assets or regulatory liabilities on the Consolidated Balance Sheets as follows (in millions):
|  | Alliant Energy |  | IPL |  | WPL
|  | 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Commodity contracts | Regulatory assets |  | ($37.9 | ) |  |  | ($79.6 | ) |  |  | ($78.4 | ) |  |  | ($16.8 | ) |  |  | ($42.4 | ) |  |  | ($47.8 | ) |  |  | ($21.1 | ) |  |  | ($37.2 | ) |  |  | ($30.6 | )
Commodity contracts | Regulatory liabilities | 20.3 |  |  | 9.3 |  |  | 11.5 |  |  | 13.5 |  |  | 6.4 |  |  | 10.6 |  |  | 6.8 |  |  | 2.9 |  |  | 0.9 |
Foreign exchange contracts | Regulatory liabilities | — |  |  | — |  |  | 3.8 |  |  | — |  |  | — |  |  | 3.8 |  |  | — |  |  | — |  |  | — |
IPL [Member] |
Derivative [Line Items] |
Notional Amounts of Derivative Instruments | As of December 31, 2012, notional amounts by delivery year related to outstanding swap contracts, option contracts, physical forward contracts, FTRs and coal contracts that were accounted for as commodity derivative instruments were as follows (units in thousands):
| 2013 |  | 2014 |  | 2015 |  | Total
Alliant Energy |  |  |  |  |  |  |
Electricity (MWhs) | 4,130 |  |  | 2,670 |  |  | 876 |  |  | 7,676 |
FTRs (MWs) | 28 |  |  | — |  |  | — |  |  | 28 |
Natural gas (dekatherms (Dths)) | 72,105 |  |  | 7,747 |  |  | 450 |  |  | 80,302 |
Coal (tons) | 896 |  |  | 981 |  |  | 562 |  |  | 2,439 |
IPL |  |  |  |  |  |  |
Electricity (MWhs) | 2,209 |  |  | 549 |  |  | — |  |  | 2,758 |
FTRs (MWs) | 15 |  |  | — |  |  | — |  |  | 15 |
Natural gas (Dths) | 57,731 |  |  | 3,535 |  |  | 225 |  |  | 61,491 |
WPL |  |  |  |  |  |  |
Electricity (MWhs) | 1,921 |  |  | 2,121 |  |  | 876 |  |  | 4,918 |
FTRs (MWs) | 13 |  |  | — |  |  | — |  |  | 13 |
Natural gas (Dths) | 14,374 |  |  | 4,212 |  |  | 225 |  |  | 18,811 |
Coal (tons) | 896 |  |  | 981 |  |  | 562 |  |  | 2,439 |
Fair Value of Financial Instruments | At December 31, the fair values of current derivative assets were included in “Prepayments and other,” non-current derivative assets were included in “Deferred charges and other,” current derivative liabilities were included in “Derivative liabilities” and non-current derivative liabilities were included in “Other long-term liabilities and deferred credits” on the Consolidated Balance Sheets as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Commodity contracts | 2012 |  | 2011 |  | 2012 |  | 2011 |  | 2012 |  | 2011
Current derivative assets |  | $23.5 |  |  |  | $12.7 |  |  |  | $17.0 |  |  |  | $9.2 |  |  |  | $6.5 |  |  |  | $3.5 |
Non-current derivative assets | 2.7 |  |  | 3.0 |  |  | 0.5 |  |  | 1.4 |  |  | 2.2 |  |  | 1.6 |
Current derivative liabilities | 31.1 |  |  | 55.9 |  |  | 14.1 |  |  | 24.5 |  |  | 17.0 |  |  | 31.4 |
Non-current derivative liabilities | 9.3 |  |  | 22.1 |  |  | 2.0 |  |  | 9.1 |  |  | 7.3 |  |  | 13.0 |
Gains and Losses from Derivative Instruments Not Designated as Hedging Instruments | Changes in unrealized gains (losses) from derivative instruments not designated as hedging instruments were recorded with offsets to regulatory assets or regulatory liabilities on the Consolidated Balance Sheets as follows (in millions):
|  | Alliant Energy |  | IPL |  | WPL
|  | 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Commodity contracts | Regulatory assets |  | ($37.9 | ) |  |  | ($79.6 | ) |  |  | ($78.4 | ) |  |  | ($16.8 | ) |  |  | ($42.4 | ) |  |  | ($47.8 | ) |  |  | ($21.1 | ) |  |  | ($37.2 | ) |  |  | ($30.6 | )
Commodity contracts | Regulatory liabilities | 20.3 |  |  | 9.3 |  |  | 11.5 |  |  | 13.5 |  |  | 6.4 |  |  | 10.6 |  |  | 6.8 |  |  | 2.9 |  |  | 0.9 |
Foreign exchange contracts | Regulatory liabilities | — |  |  | — |  |  | 3.8 |  |  | — |  |  | — |  |  | 3.8 |  |  | — |  |  | — |  |  | — |
WPL [Member] |
Derivative [Line Items] |
Notional Amounts of Derivative Instruments | As of December 31, 2012, notional amounts by delivery year related to outstanding swap contracts, option contracts, physical forward contracts, FTRs and coal contracts that were accounted for as commodity derivative instruments were as follows (units in thousands):
| 2013 |  | 2014 |  | 2015 |  | Total
Alliant Energy |  |  |  |  |  |  |
Electricity (MWhs) | 4,130 |  |  | 2,670 |  |  | 876 |  |  | 7,676 |
FTRs (MWs) | 28 |  |  | — |  |  | — |  |  | 28 |
Natural gas (dekatherms (Dths)) | 72,105 |  |  | 7,747 |  |  | 450 |  |  | 80,302 |
Coal (tons) | 896 |  |  | 981 |  |  | 562 |  |  | 2,439 |
IPL |  |  |  |  |  |  |
Electricity (MWhs) | 2,209 |  |  | 549 |  |  | — |  |  | 2,758 |
FTRs (MWs) | 15 |  |  | — |  |  | — |  |  | 15 |
Natural gas (Dths) | 57,731 |  |  | 3,535 |  |  | 225 |  |  | 61,491 |
WPL |  |  |  |  |  |  |
Electricity (MWhs) | 1,921 |  |  | 2,121 |  |  | 876 |  |  | 4,918 |
FTRs (MWs) | 13 |  |  | — |  |  | — |  |  | 13 |
Natural gas (Dths) | 14,374 |  |  | 4,212 |  |  | 225 |  |  | 18,811 |
Coal (tons) | 896 |  |  | 981 |  |  | 562 |  |  | 2,439 |
Fair Value of Financial Instruments | At December 31, the fair values of current derivative assets were included in “Prepayments and other,” non-current derivative assets were included in “Deferred charges and other,” current derivative liabilities were included in “Derivative liabilities” and non-current derivative liabilities were included in “Other long-term liabilities and deferred credits” on the Consolidated Balance Sheets as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Commodity contracts | 2012 |  | 2011 |  | 2012 |  | 2011 |  | 2012 |  | 2011
Current derivative assets |  | $23.5 |  |  |  | $12.7 |  |  |  | $17.0 |  |  |  | $9.2 |  |  |  | $6.5 |  |  |  | $3.5 |
Non-current derivative assets | 2.7 |  |  | 3.0 |  |  | 0.5 |  |  | 1.4 |  |  | 2.2 |  |  | 1.6 |
Current derivative liabilities | 31.1 |  |  | 55.9 |  |  | 14.1 |  |  | 24.5 |  |  | 17.0 |  |  | 31.4 |
Non-current derivative liabilities | 9.3 |  |  | 22.1 |  |  | 2.0 |  |  | 9.1 |  |  | 7.3 |  |  | 13.0 |
Gains and Losses from Derivative Instruments Not Designated as Hedging Instruments | Changes in unrealized gains (losses) from derivative instruments not designated as hedging instruments were recorded with offsets to regulatory assets or regulatory liabilities on the Consolidated Balance Sheets as follows (in millions):
|  | Alliant Energy |  | IPL |  | WPL
|  | 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Commodity contracts | Regulatory assets |  | ($37.9 | ) |  |  | ($79.6 | ) |  |  | ($78.4 | ) |  |  | ($16.8 | ) |  |  | ($42.4 | ) |  |  | ($47.8 | ) |  |  | ($21.1 | ) |  |  | ($37.2 | ) |  |  | ($30.6 | )
Commodity contracts | Regulatory liabilities | 20.3 |  |  | 9.3 |  |  | 11.5 |  |  | 13.5 |  |  | 6.4 |  |  | 10.6 |  |  | 6.8 |  |  | 2.9 |  |  | 0.9 |
Foreign exchange contracts | Regulatory liabilities | — |  |  | — |  |  | 3.8 |  |  | — |  |  | — |  |  | 3.8 |  |  | — |  |  | — |  |  | — |

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- Definition Tabular disclosure of the location and amount of gains and losses reported in the statement of financial performance, or when applicable, the statement of financial position. For example, (a) gains and losses recognized in the income statement on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges and (b) gains and losses initially recognized in other comprehensive income on derivative instruments designated and qualifying as cash flow hedges. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959 + Details
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- Definition Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition Tabular disclosure of the notional amounts of outstanding derivative positions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959 + Details
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