Related Parties (Tables)

9 Months Ended

Sep. 30, 2017

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
	2017		2016		2017		2016		2017		2016		2017		2016
Corporate Services billings		$48		$41		$130		$124		$37		$33		$100		$103
Sales credited	8		4		15		7		6		3		8		6
Purchases billed	109		126		271		324		32		23		99		65

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2017	December 31, 2016	September 30, 2017	December 31, 2016
Net payables to Corporate Services	$118	$104	$64	$72

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
	2017		2016		2017		2016
ATC LLC billings to WPL		$26		$28		$79		$82
WPL billings to ATC LLC	2		4		8		10

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
	2017		2016		2017		2016		2017		2016		2017		2016
Corporate Services billings		$48		$41		$130		$124		$37		$33		$100		$103
Sales credited	8		4		15		7		6		3		8		6
Purchases billed	109		126		271		324		32		23		99		65

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2017	December 31, 2016	September 30, 2017	December 31, 2016
Net payables to Corporate Services	$118	$104	$64	$72

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
	2017		2016		2017		2016		2017		2016		2017		2016
Corporate Services billings		$48		$41		$130		$124		$37		$33		$100		$103
Sales credited	8		4		15		7		6		3		8		6
Purchases billed	109		126		271		324		32		23		99		65

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2017	December 31, 2016	September 30, 2017	December 31, 2016
Net payables to Corporate Services	$118	$104	$64	$72

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
	2017		2016		2017		2016
ATC LLC billings to WPL		$26		$28		$79		$82
WPL billings to ATC LLC	2		4		8		10