Related Parties (Tables)

6 Months Ended

Jun. 30, 2015

Related Party Transactions [Line Items]

Services Provided, Sales Credited And Purchases

The amounts billed for services provided, sales credited and purchases for the three and six months ended June 30 were as follows (in millions):

	IPL								WPL
	Three Months				Six Months				Three Months				Six Months
	2015		2014		2015		2014		2015		2014		2015		2014
Corporate Services billings		$40		$41		$76		$74		$32		$31		$60		$59
Sales credited	2		2		6		4		6		3		12		2
Purchases billed	89		108		168		207		19		28		33		58

Net Intercompany Payables

Net intercompany payables to Corporate Services were as follows (in millions):

	IPL		WPL
	June 30, 2015	December 31, 2014	June 30, 2015	December 31, 2014
Net payables to Corporate Services	$95	$84	$49	$58

Related Amounts Billed Between Parties

The related amounts billed between the parties for the three and six months ended June 30 were as follows (in millions):

	Three Months				Six Months
	2015		2014		2015		2014
ATC billings to WPL		$25		$24		$50		$48
WPL billings to ATC	3		1		5		4

IPL [Member]

Related Party Transactions [Line Items]

Services Provided, Sales Credited And Purchases

The amounts billed for services provided, sales credited and purchases for the three and six months ended June 30 were as follows (in millions):

	IPL								WPL
	Three Months				Six Months				Three Months				Six Months
	2015		2014		2015		2014		2015		2014		2015		2014
Corporate Services billings		$40		$41		$76		$74		$32		$31		$60		$59
Sales credited	2		2		6		4		6		3		12		2
Purchases billed	89		108		168		207		19		28		33		58

Net Intercompany Payables

Net intercompany payables to Corporate Services were as follows (in millions):

	IPL		WPL
	June 30, 2015	December 31, 2014	June 30, 2015	December 31, 2014
Net payables to Corporate Services	$95	$84	$49	$58

WPL [Member]

Related Party Transactions [Line Items]

Services Provided, Sales Credited And Purchases

The amounts billed for services provided, sales credited and purchases for the three and six months ended June 30 were as follows (in millions):

	IPL								WPL
	Three Months				Six Months				Three Months				Six Months
	2015		2014		2015		2014		2015		2014		2015		2014
Corporate Services billings		$40		$41		$76		$74		$32		$31		$60		$59
Sales credited	2		2		6		4		6		3		12		2
Purchases billed	89		108		168		207		19		28		33		58

Net Intercompany Payables

Net intercompany payables to Corporate Services were as follows (in millions):

	IPL		WPL
	June 30, 2015	December 31, 2014	June 30, 2015	December 31, 2014
Net payables to Corporate Services	$95	$84	$49	$58

Related Amounts Billed Between Parties

The related amounts billed between the parties for the three and six months ended June 30 were as follows (in millions):

	Three Months				Six Months
	2015		2014		2015		2014
ATC billings to WPL		$25		$24		$50		$48
WPL billings to ATC	3		1		5		4