Related Parties (Tables)

6 Months Ended

Jun. 30, 2016

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
	2016		2015		2016		2015		2016		2015		2016		2015
Corporate Services billings		$45		$40		$83		$76		$37		$32		$70		$60
Sales credited	2		2		3		6		2		6		3		12
Purchases billed	102		89		198		168		23		19		42		33

Net Intercompany Payables

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

	IPL		WPL
	June 30, 2016	December 31, 2015	June 30, 2016	December 31, 2015
Net payables to Corporate Services	$102	$93	$62	$54

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
	2016		2015		2016		2015
ATC billings to WPL		$27		$25		$54		$50
WPL billings to ATC	3		3		6		5

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
	2016		2015		2016		2015		2016		2015		2016		2015
Corporate Services billings		$45		$40		$83		$76		$37		$32		$70		$60
Sales credited	2		2		3		6		2		6		3		12
Purchases billed	102		89		198		168		23		19		42		33

Net Intercompany Payables

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

	IPL		WPL
	June 30, 2016	December 31, 2015	June 30, 2016	December 31, 2015
Net payables to Corporate Services	$102	$93	$62	$54

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
	2016		2015		2016		2015		2016		2015		2016		2015
Corporate Services billings		$45		$40		$83		$76		$37		$32		$70		$60
Sales credited	2		2		3		6		2		6		3		12
Purchases billed	102		89		198		168		23		19		42		33

Net Intercompany Payables

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

	IPL		WPL
	June 30, 2016	December 31, 2015	June 30, 2016	December 31, 2015
Net payables to Corporate Services	$102	$93	$62	$54

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
	2016		2015		2016		2015
ATC billings to WPL		$27		$25		$54		$50
WPL billings to ATC	3		3		6		5