Related Parties

12 Months Ended

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.