Related Parties (Tables)

9 Months Ended

Sep. 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 nine months ended September 30 were as follows (in millions):

	IPL								WPL
	Three Months				Nine Months				Three Months				Nine Months
	2016		2015		2016		2015		2016		2015		2016		2015
Corporate Services billings		$41		$38		$124		$114		$33		$30		$103		$90
Sales credited	4		2		7		8		3		9		6		21
Purchases billed	126		110		324		278		23		16		65		49

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2016	December 31, 2015	September 30, 2016	December 31, 2015
Net payables to Corporate Services	$114	$93	$68	$54

Related Amounts Billed Between Parties

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

	Three Months				Nine Months
	2016		2015		2016		2015
ATC billings to WPL		$28		$25		$82		$75
WPL billings to ATC	4		4		10		9

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 nine months ended September 30 were as follows (in millions):

	IPL								WPL
	Three Months				Nine Months				Three Months				Nine Months
	2016		2015		2016		2015		2016		2015		2016		2015
Corporate Services billings		$41		$38		$124		$114		$33		$30		$103		$90
Sales credited	4		2		7		8		3		9		6		21
Purchases billed	126		110		324		278		23		16		65		49

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2016	December 31, 2015	September 30, 2016	December 31, 2015
Net payables to Corporate Services	$114	$93	$68	$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 nine months ended September 30 were as follows (in millions):

	IPL								WPL
	Three Months				Nine Months				Three Months				Nine Months
	2016		2015		2016		2015		2016		2015		2016		2015
Corporate Services billings		$41		$38		$124		$114		$33		$30		$103		$90
Sales credited	4		2		7		8		3		9		6		21
Purchases billed	126		110		324		278		23		16		65		49

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2016	December 31, 2015	September 30, 2016	December 31, 2015
Net payables to Corporate Services	$114	$93	$68	$54

Related Amounts Billed Between Parties

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

	Three Months				Nine Months
	2016		2015		2016		2015
ATC billings to WPL		$28		$25		$82		$75
WPL billings to ATC	4		4		10		9