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Related Parties | 12 Months Ended
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Dec. 31, 2012
Related Party Transaction [Line Items] |
Related Parties | RELATED PARTIES System Coordination and Operating Agreement - IPL and WPL are parties to a system coordination and operating agreement whereby Corporate Services serves as agent on behalf of IPL and WPL. The agreement, which has been approved or reviewed by FERC and all state regulatory bodies having jurisdiction, provides a contractual basis for coordinated planning, construction, operation and maintenance of the interconnected electric generation systems of IPL and WPL. As agent of the agreement, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions. Corporate Services allocates such sales and purchases among IPL and WPL based on procedures included in the agreement. The sales credited to and purchases billed to IPL and WPL were as follows (in millions):
| IPL |  | WPL
| 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Sales credited |  | $10 |  |  |  | $31 |  |  |  | $28 |  |  |  | $14 |  |  |  | $28 |  |  |  | $24 |
Purchases billed | 301 |  |  | 307 |  |  | 341 |  |  | 61 |  |  | 77 |  |  | 73 |
Service Agreement - Pursuant to a service agreement, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation, benefits and fees associated with various professional services. In 2012, Corporate Services executed a revised service agreement with IPL and WPL and began including a return on net assets as part of its billings to IPL and WPL. The amounts billed to IPL and WPL were as follows (in millions):
| IPL |  | WPL
| 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Corporate Services billings |  | $129 |  |  |  | $153 |  |  |  | $170 |  |  |  | $102 |  |  |  | $119 |  |  |  | $127 |
As of December 31, net intercompany payables to Corporate Services were as follows (in millions):
| 2012 |  | 2011
IPL |  | $72 |  |  |  | $82 |
WPL | 40 |  |  | 48 |
ATC - Pursuant to various agreements, WPL receives a range of transmission services from ATC. WPL provides operation, maintenance, and construction services to ATC. WPL and ATC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties were as follows (in millions):
| 2012 |  | 2011 |  | 2010
ATC billings to WPL |  | $90 |  |  |  | $90 |  |  |  | $92 |
WPL billings to ATC | 11 |  |  | 12 |  |  | 11 |
As of December 31, 2012 and 2011, WPL owed ATC net amounts of $6 million and $6 million, respectively. IPL’s Sale of Certain Wind Project Assets to Resources - Pursuant to a wind development asset purchase and sale agreement, IPL sold Resources wind project assets for the Franklin County wind project at cost in 2011 for $115.3 million. Refer to Note 1(e) for additional information. WPL’s Sheboygan Falls Energy Facility Lease - Refer to Note 3(b) for discussion of WPL’s Sheboygan Falls Energy Facility lease.
IPL [Member] |
Related Party Transaction [Line Items] |
Related Parties | RELATED PARTIES System Coordination and Operating Agreement - IPL and WPL are parties to a system coordination and operating agreement whereby Corporate Services serves as agent on behalf of IPL and WPL. The agreement, which has been approved or reviewed by FERC and all state regulatory bodies having jurisdiction, provides a contractual basis for coordinated planning, construction, operation and maintenance of the interconnected electric generation systems of IPL and WPL. As agent of the agreement, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions. Corporate Services allocates such sales and purchases among IPL and WPL based on procedures included in the agreement. The sales credited to and purchases billed to IPL and WPL were as follows (in millions):
| IPL |  | WPL
| 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Sales credited |  | $10 |  |  |  | $31 |  |  |  | $28 |  |  |  | $14 |  |  |  | $28 |  |  |  | $24 |
Purchases billed | 301 |  |  | 307 |  |  | 341 |  |  | 61 |  |  | 77 |  |  | 73 |
Service Agreement - Pursuant to a service agreement, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation, benefits and fees associated with various professional services. In 2012, Corporate Services executed a revised service agreement with IPL and WPL and began including a return on net assets as part of its billings to IPL and WPL. The amounts billed to IPL and WPL were as follows (in millions):
| IPL |  | WPL
| 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Corporate Services billings |  | $129 |  |  |  | $153 |  |  |  | $170 |  |  |  | $102 |  |  |  | $119 |  |  |  | $127 |
As of December 31, net intercompany payables to Corporate Services were as follows (in millions):
| 2012 |  | 2011
IPL |  | $72 |  |  |  | $82 |
WPL | 40 |  |  | 48 |
ATC - Pursuant to various agreements, WPL receives a range of transmission services from ATC. WPL provides operation, maintenance, and construction services to ATC. WPL and ATC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties were as follows (in millions):
| 2012 |  | 2011 |  | 2010
ATC billings to WPL |  | $90 |  |  |  | $90 |  |  |  | $92 |
WPL billings to ATC | 11 |  |  | 12 |  |  | 11 |
As of December 31, 2012 and 2011, WPL owed ATC net amounts of $6 million and $6 million, respectively. IPL’s Sale of Certain Wind Project Assets to Resources - Pursuant to a wind development asset purchase and sale agreement, IPL sold Resources wind project assets for the Franklin County wind project at cost in 2011 for $115.3 million. Refer to Note 1(e) for additional information. WPL’s Sheboygan Falls Energy Facility Lease - Refer to Note 3(b) for discussion of WPL’s Sheboygan Falls Energy Facility lease.
WPL [Member] |
Related Party Transaction [Line Items] |
Related Parties | RELATED PARTIES System Coordination and Operating Agreement - IPL and WPL are parties to a system coordination and operating agreement whereby Corporate Services serves as agent on behalf of IPL and WPL. The agreement, which has been approved or reviewed by FERC and all state regulatory bodies having jurisdiction, provides a contractual basis for coordinated planning, construction, operation and maintenance of the interconnected electric generation systems of IPL and WPL. As agent of the agreement, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions. Corporate Services allocates such sales and purchases among IPL and WPL based on procedures included in the agreement. The sales credited to and purchases billed to IPL and WPL were as follows (in millions):
| IPL |  | WPL
| 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Sales credited |  | $10 |  |  |  | $31 |  |  |  | $28 |  |  |  | $14 |  |  |  | $28 |  |  |  | $24 |
Purchases billed | 301 |  |  | 307 |  |  | 341 |  |  | 61 |  |  | 77 |  |  | 73 |
Service Agreement - Pursuant to a service agreement, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation, benefits and fees associated with various professional services. In 2012, Corporate Services executed a revised service agreement with IPL and WPL and began including a return on net assets as part of its billings to IPL and WPL. The amounts billed to IPL and WPL were as follows (in millions):
| IPL |  | WPL
| 2012 |  | 2011 |  | 2010 |  | 2012 |  | 2011 |  | 2010
Corporate Services billings |  | $129 |  |  |  | $153 |  |  |  | $170 |  |  |  | $102 |  |  |  | $119 |  |  |  | $127 |
As of December 31, net intercompany payables to Corporate Services were as follows (in millions):
| 2012 |  | 2011
IPL |  | $72 |  |  |  | $82 |
WPL | 40 |  |  | 48 |
ATC - Pursuant to various agreements, WPL receives a range of transmission services from ATC. WPL provides operation, maintenance, and construction services to ATC. WPL and ATC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties were as follows (in millions):
| 2012 |  | 2011 |  | 2010
ATC billings to WPL |  | $90 |  |  |  | $90 |  |  |  | $92 |
WPL billings to ATC | 11 |  |  | 12 |  |  | 11 |
As of December 31, 2012 and 2011, WPL owed ATC net amounts of $6 million and $6 million, respectively. IPL’s Sale of Certain Wind Project Assets to Resources - Pursuant to a wind development asset purchase and sale agreement, IPL sold Resources wind project assets for the Franklin County wind project at cost in 2011 for $115.3 million. Refer to Note 1(e) for additional information. WPL’s Sheboygan Falls Energy Facility Lease - Refer to Note 3(b) for discussion of WPL’s Sheboygan Falls Energy Facility lease.

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- Definition The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39691-107864 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 1-4 -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 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39678-107864 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)) -URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph b -Article 3A Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Article 4 + Details
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