Related Parties (Tables)

9 Months Ended

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

	IPL								WPL
	Three Months				Nine Months				Three Months				Nine Months
	2015		2014		2015		2014		2015		2014		2015		2014
Corporate Services billings		$38		$37		$114		$111		$30		$30		$90		$89
Sales credited	2		2		8		6		9		2		21		4
Purchases billed	110		106		278		313		16		34		49		92

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2015	December 31, 2014	September 30, 2015	December 31, 2014
Net payables to Corporate Services	$101	$84	$55	$58

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
	2015		2014		2015		2014
ATC billings to WPL		$25		$24		$75		$72
WPL billings to ATC	4		3		9		7

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
	2015		2014		2015		2014		2015		2014		2015		2014
Corporate Services billings		$38		$37		$114		$111		$30		$30		$90		$89
Sales credited	2		2		8		6		9		2		21		4
Purchases billed	110		106		278		313		16		34		49		92

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2015	December 31, 2014	September 30, 2015	December 31, 2014
Net payables to Corporate Services	$101	$84	$55	$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 nine months ended September 30 were as follows (in millions):

	IPL								WPL
	Three Months				Nine Months				Three Months				Nine Months
	2015		2014		2015		2014		2015		2014		2015		2014
Corporate Services billings		$38		$37		$114		$111		$30		$30		$90		$89
Sales credited	2		2		8		6		9		2		21		4
Purchases billed	110		106		278		313		16		34		49		92

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2015	December 31, 2014	September 30, 2015	December 31, 2014
Net payables to Corporate Services	$101	$84	$55	$58

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
	2015		2014		2015		2014
ATC billings to WPL		$25		$24		$75		$72
WPL billings to ATC	4		3		9		7