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Commitments And Contingencies (Tables) | 12 Months Ended
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Dec. 31, 2014
Long-term Purchase Commitment [Line Items] |
Operating Expense Purchase Obligations | At December 31, 2014, minimum future commitments related to these operating expense purchase obligations were as follows (in millions):
Alliant Energy | 2015 |  | 2016 |  | 2017 |  | 2018 |  | 2019 |  | Thereafter |  | Total
Purchased power (a): |  |  |  |  |  |  |  |  |  |  |  |  |
DAEC (IPL) (b) |  | $119 |  |  |  | $125 |  |  |  | $138 |  |  |  | $131 |  |  |  | $143 |  |  |  | $882 |  |  |  | $1,538 |
Other | 74 |  |  | 46 |  |  | 44 |  |  | 44 |  |  | — |  |  | — |  |  | 208 |
| 193 |  |  | 171 |  |  | 182 |  |  | 175 |  |  | 143 |  |  | 882 |  |  | 1,746 |
Natural gas | 175 |  |  | 69 |  |  | 23 |  |  | 5 |  |  | 2 |  |  | 4 |  |  | 278 |
Coal (c) | 124 |  |  | 78 |  |  | 47 |  |  | 34 |  |  | 8 |  |  | — |  |  | 291 |
SO2 emission allowances (d) | 12 |  |  | 14 |  |  | 8 |  |  | — |  |  | — |  |  | — |  |  | 34 |
Other (e) | 10 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 11 |
|  | $514 |  |  |  | $333 |  |  |  | $260 |  |  |  | $214 |  |  |  | $153 |  |  |  | $886 |  |  |  | $2,360 |
IPL | 2015 |  | 2016 |  | 2017 |  | 2018 |  | 2019 |  | Thereafter |  | Total
Purchased power (a): |  |  |  |  |  |  |  |  |  |  |  |  |
DAEC (b) |  | $119 |  |  |  | $125 |  |  |  | $138 |  |  |  | $131 |  |  |  | $143 |  |  |  | $882 |  |  |  | $1,538 |
Other | — |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 1 |
| 119 |  |  | 126 |  |  | 138 |  |  | 131 |  |  | 143 |  |  | 882 |  |  | 1,539 |
Natural gas | 108 |  |  | 32 |  |  | 5 |  |  | 2 |  |  | 2 |  |  | 4 |  |  | 153 |
Coal (c) | 61 |  |  | 35 |  |  | 20 |  |  | 11 |  |  | — |  |  | — |  |  | 127 |
SO2 emission allowances (d) | 12 |  |  | 14 |  |  | 8 |  |  | — |  |  | — |  |  | — |  |  | 34 |
Other (e) | 6 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 6 |
| $306 |  |  | $207 |  |  |  | $171 |  |  |  | $144 |  |  |  | $145 |  |  |  | $886 |  |  |  | $1,859 |
WPL | 2015 |  | 2016 |  | 2017 |  | 2018 |  | 2019 |  | Thereafter |  | Total
Purchased power (a) |  | $74 |  |  |  | $45 |  |  |  | $44 |  |  |  | $44 |  |  |  | $— |  |  |  | $— |  |  |  | $207 |
Natural gas | 67 |  |  | 37 |  |  | 18 |  |  | 3 |  |  | — |  |  | — |  |  | 125 |
Coal (c) | 63 |  |  | 43 |  |  | 27 |  |  | 23 |  |  | 8 |  |  | — |  |  | 164 |
Other (e) | 2 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 3 |
|  | $206 |  |  |  | $126 |  |  |  | $89 |  |  |  | $70 |  |  |  | $8 |  |  |  | $— |  |  |  | $499 |
(a) | Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased. Refer to Note 18 for additional information on purchased power transactions.
(b) | Includes commitments incurred under a PPA, which grants IPL rights to purchase up to 431 MWs of capacity and the resulting energy from DAEC for a term through December 31, 2025. If energy delivered is less than the targeted energy amount, an adjustment payment will be made to IPL, which will be reflected in IPL’s fuel adjustment clause.
(c) | Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of December 31, 2014 regarding expected future usage, which is subject to change.
(d) | Refer to Note 2 for discussion of $34 million of charges recognized by Alliant Energy and IPL in 2011 for forward contracts to purchase SO2 emission allowances.
(e) | Includes individual commitments incurred during the normal course of business that exceeded $1 million at December 31, 2014.
Schedule of Environmental Liabilities | At December 31, 2014, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Range of estimated future costs |  | $12 |  | - | $31 |  |  | $11 |  | - | $29 |  |  | $1 |  | - | $2
Current and non-current environmental liabilities | 16 |  | 14 |  | 2
At December 31, current environmental liabilities were included in “Other current liabilities” and non-current environmental liabilities were included in “Other liabilities” on the balance sheets as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2014 |  | 2013 |  | 2014 |  | 2013 |  | 2014 |  | 2013
Current environmental liabilities |  | $2.0 |  |  |  | $3.6 |  |  |  | $1.7 |  |  |  | $2.8 |  |  |  | $0.3 |  |  |  | $0.8 |
Non-current environmental liabilities | 13.5 |  |  | 15.4 |  |  | 11.9 |  |  | 13.6 |  |  | 1.6 |  |  | 1.7 |
|  | $15.5 |  |  |  | $19.0 |  |  |  | $13.6 |  |  |  | $16.4 |  |  |  | $1.9 |  |  |  | $2.5 |
IPL [Member] |
Long-term Purchase Commitment [Line Items] |
Operating Expense Purchase Obligations | At December 31, 2014, minimum future commitments related to these operating expense purchase obligations were as follows (in millions):
Alliant Energy | 2015 |  | 2016 |  | 2017 |  | 2018 |  | 2019 |  | Thereafter |  | Total
Purchased power (a): |  |  |  |  |  |  |  |  |  |  |  |  |
DAEC (IPL) (b) |  | $119 |  |  |  | $125 |  |  |  | $138 |  |  |  | $131 |  |  |  | $143 |  |  |  | $882 |  |  |  | $1,538 |
Other | 74 |  |  | 46 |  |  | 44 |  |  | 44 |  |  | — |  |  | — |  |  | 208 |
| 193 |  |  | 171 |  |  | 182 |  |  | 175 |  |  | 143 |  |  | 882 |  |  | 1,746 |
Natural gas | 175 |  |  | 69 |  |  | 23 |  |  | 5 |  |  | 2 |  |  | 4 |  |  | 278 |
Coal (c) | 124 |  |  | 78 |  |  | 47 |  |  | 34 |  |  | 8 |  |  | — |  |  | 291 |
SO2 emission allowances (d) | 12 |  |  | 14 |  |  | 8 |  |  | — |  |  | — |  |  | — |  |  | 34 |
Other (e) | 10 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 11 |
|  | $514 |  |  |  | $333 |  |  |  | $260 |  |  |  | $214 |  |  |  | $153 |  |  |  | $886 |  |  |  | $2,360 |
IPL | 2015 |  | 2016 |  | 2017 |  | 2018 |  | 2019 |  | Thereafter |  | Total
Purchased power (a): |  |  |  |  |  |  |  |  |  |  |  |  |
DAEC (b) |  | $119 |  |  |  | $125 |  |  |  | $138 |  |  |  | $131 |  |  |  | $143 |  |  |  | $882 |  |  |  | $1,538 |
Other | — |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 1 |
| 119 |  |  | 126 |  |  | 138 |  |  | 131 |  |  | 143 |  |  | 882 |  |  | 1,539 |
Natural gas | 108 |  |  | 32 |  |  | 5 |  |  | 2 |  |  | 2 |  |  | 4 |  |  | 153 |
Coal (c) | 61 |  |  | 35 |  |  | 20 |  |  | 11 |  |  | — |  |  | — |  |  | 127 |
SO2 emission allowances (d) | 12 |  |  | 14 |  |  | 8 |  |  | — |  |  | — |  |  | — |  |  | 34 |
Other (e) | 6 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 6 |
| $306 |  |  | $207 |  |  |  | $171 |  |  |  | $144 |  |  |  | $145 |  |  |  | $886 |  |  |  | $1,859 |
WPL | 2015 |  | 2016 |  | 2017 |  | 2018 |  | 2019 |  | Thereafter |  | Total
Purchased power (a) |  | $74 |  |  |  | $45 |  |  |  | $44 |  |  |  | $44 |  |  |  | $— |  |  |  | $— |  |  |  | $207 |
Natural gas | 67 |  |  | 37 |  |  | 18 |  |  | 3 |  |  | — |  |  | — |  |  | 125 |
Coal (c) | 63 |  |  | 43 |  |  | 27 |  |  | 23 |  |  | 8 |  |  | — |  |  | 164 |
Other (e) | 2 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 3 |
|  | $206 |  |  |  | $126 |  |  |  | $89 |  |  |  | $70 |  |  |  | $8 |  |  |  | $— |  |  |  | $499 |
(a) | Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased. Refer to Note 18 for additional information on purchased power transactions.
(b) | Includes commitments incurred under a PPA, which grants IPL rights to purchase up to 431 MWs of capacity and the resulting energy from DAEC for a term through December 31, 2025. If energy delivered is less than the targeted energy amount, an adjustment payment will be made to IPL, which will be reflected in IPL’s fuel adjustment clause.
(c) | Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of December 31, 2014 regarding expected future usage, which is subject to change.
(d) | Refer to Note 2 for discussion of $34 million of charges recognized by Alliant Energy and IPL in 2011 for forward contracts to purchase SO2 emission allowances.
(e) | Includes individual commitments incurred during the normal course of business that exceeded $1 million at December 31, 2014.
Schedule of Environmental Liabilities | At December 31, 2014, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Range of estimated future costs |  | $12 |  | - | $31 |  |  | $11 |  | - | $29 |  |  | $1 |  | - | $2
Current and non-current environmental liabilities | 16 |  | 14 |  | 2
At December 31, current environmental liabilities were included in “Other current liabilities” and non-current environmental liabilities were included in “Other liabilities” on the balance sheets as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2014 |  | 2013 |  | 2014 |  | 2013 |  | 2014 |  | 2013
Current environmental liabilities |  | $2.0 |  |  |  | $3.6 |  |  |  | $1.7 |  |  |  | $2.8 |  |  |  | $0.3 |  |  |  | $0.8 |
Non-current environmental liabilities | 13.5 |  |  | 15.4 |  |  | 11.9 |  |  | 13.6 |  |  | 1.6 |  |  | 1.7 |
|  | $15.5 |  |  |  | $19.0 |  |  |  | $13.6 |  |  |  | $16.4 |  |  |  | $1.9 |  |  |  | $2.5 |
WPL [Member] |
Long-term Purchase Commitment [Line Items] |
Operating Expense Purchase Obligations | At December 31, 2014, minimum future commitments related to these operating expense purchase obligations were as follows (in millions):
Alliant Energy | 2015 |  | 2016 |  | 2017 |  | 2018 |  | 2019 |  | Thereafter |  | Total
Purchased power (a): |  |  |  |  |  |  |  |  |  |  |  |  |
DAEC (IPL) (b) |  | $119 |  |  |  | $125 |  |  |  | $138 |  |  |  | $131 |  |  |  | $143 |  |  |  | $882 |  |  |  | $1,538 |
Other | 74 |  |  | 46 |  |  | 44 |  |  | 44 |  |  | — |  |  | — |  |  | 208 |
| 193 |  |  | 171 |  |  | 182 |  |  | 175 |  |  | 143 |  |  | 882 |  |  | 1,746 |
Natural gas | 175 |  |  | 69 |  |  | 23 |  |  | 5 |  |  | 2 |  |  | 4 |  |  | 278 |
Coal (c) | 124 |  |  | 78 |  |  | 47 |  |  | 34 |  |  | 8 |  |  | — |  |  | 291 |
SO2 emission allowances (d) | 12 |  |  | 14 |  |  | 8 |  |  | — |  |  | — |  |  | — |  |  | 34 |
Other (e) | 10 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 11 |
|  | $514 |  |  |  | $333 |  |  |  | $260 |  |  |  | $214 |  |  |  | $153 |  |  |  | $886 |  |  |  | $2,360 |
IPL | 2015 |  | 2016 |  | 2017 |  | 2018 |  | 2019 |  | Thereafter |  | Total
Purchased power (a): |  |  |  |  |  |  |  |  |  |  |  |  |
DAEC (b) |  | $119 |  |  |  | $125 |  |  |  | $138 |  |  |  | $131 |  |  |  | $143 |  |  |  | $882 |  |  |  | $1,538 |
Other | — |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 1 |
| 119 |  |  | 126 |  |  | 138 |  |  | 131 |  |  | 143 |  |  | 882 |  |  | 1,539 |
Natural gas | 108 |  |  | 32 |  |  | 5 |  |  | 2 |  |  | 2 |  |  | 4 |  |  | 153 |
Coal (c) | 61 |  |  | 35 |  |  | 20 |  |  | 11 |  |  | — |  |  | — |  |  | 127 |
SO2 emission allowances (d) | 12 |  |  | 14 |  |  | 8 |  |  | — |  |  | — |  |  | — |  |  | 34 |
Other (e) | 6 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 6 |
| $306 |  |  | $207 |  |  |  | $171 |  |  |  | $144 |  |  |  | $145 |  |  |  | $886 |  |  |  | $1,859 |
WPL | 2015 |  | 2016 |  | 2017 |  | 2018 |  | 2019 |  | Thereafter |  | Total
Purchased power (a) |  | $74 |  |  |  | $45 |  |  |  | $44 |  |  |  | $44 |  |  |  | $— |  |  |  | $— |  |  |  | $207 |
Natural gas | 67 |  |  | 37 |  |  | 18 |  |  | 3 |  |  | — |  |  | — |  |  | 125 |
Coal (c) | 63 |  |  | 43 |  |  | 27 |  |  | 23 |  |  | 8 |  |  | — |  |  | 164 |
Other (e) | 2 |  |  | 1 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 3 |
|  | $206 |  |  |  | $126 |  |  |  | $89 |  |  |  | $70 |  |  |  | $8 |  |  |  | $— |  |  |  | $499 |
(a) | Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased. Refer to Note 18 for additional information on purchased power transactions.
(b) | Includes commitments incurred under a PPA, which grants IPL rights to purchase up to 431 MWs of capacity and the resulting energy from DAEC for a term through December 31, 2025. If energy delivered is less than the targeted energy amount, an adjustment payment will be made to IPL, which will be reflected in IPL’s fuel adjustment clause.
(c) | Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of December 31, 2014 regarding expected future usage, which is subject to change.
(d) | Refer to Note 2 for discussion of $34 million of charges recognized by Alliant Energy and IPL in 2011 for forward contracts to purchase SO2 emission allowances.
(e) | Includes individual commitments incurred during the normal course of business that exceeded $1 million at December 31, 2014.
Schedule of Environmental Liabilities | At December 31, 2014, estimated future costs expected to be incurred for the investigation, remediation and monitoring of the MGP sites, as well as environmental liabilities recorded on the balance sheets for these sites, were as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Range of estimated future costs |  | $12 |  | - | $31 |  |  | $11 |  | - | $29 |  |  | $1 |  | - | $2
Current and non-current environmental liabilities | 16 |  | 14 |  | 2
At December 31, current environmental liabilities were included in “Other current liabilities” and non-current environmental liabilities were included in “Other liabilities” on the balance sheets as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
| 2014 |  | 2013 |  | 2014 |  | 2013 |  | 2014 |  | 2013
Current environmental liabilities |  | $2.0 |  |  |  | $3.6 |  |  |  | $1.7 |  |  |  | $2.8 |  |  |  | $0.3 |  |  |  | $0.8 |
Non-current environmental liabilities | 13.5 |  |  | 15.4 |  |  | 11.9 |  |  | 13.6 |  |  | 1.6 |  |  | 1.7 |
|  | $15.5 |  |  |  | $19.0 |  |  |  | $13.6 |  |  |  | $16.4 |  |  |  | $1.9 |  |  |  | $2.5 |

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- Definition Tabular disclosure of material liabilities for remediation, site restoration, postclosure, monitoring commitments, or other exit costs that may occur on the sale, disposal or abandonment of a property as a result of unanticipated contamination of the assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 5.Y.Q4) -URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 5 -Section Y -Paragraph Question 4 + Details
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