Related Parties (Tables)

9 Months Ended

Sep. 30, 2018

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
	2018		2017		2018		2017		2018		2017		2018		2017
Corporate Services billings		$43		$48		$128		$130		$33		$37		$100		$100
Sales credited	11		8		34		15		7		6		16		8
Purchases billed	95		109		268		271		19		32		56		99

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2018	December 31, 2017	September 30, 2018	December 31, 2017
Net payables to Corporate Services	$109	$114	$65	$61

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
	2018		2017		2018		2017
ATC billings to WPL		$26		$26		$79		$79
WPL billings to ATC	3		2		8		8

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
	2018		2017		2018		2017		2018		2017		2018		2017
Corporate Services billings		$43		$48		$128		$130		$33		$37		$100		$100
Sales credited	11		8		34		15		7		6		16		8
Purchases billed	95		109		268		271		19		32		56		99

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2018	December 31, 2017	September 30, 2018	December 31, 2017
Net payables to Corporate Services	$109	$114	$65	$61

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
	2018		2017		2018		2017		2018		2017		2018		2017
Corporate Services billings		$43		$48		$128		$130		$33		$37		$100		$100
Sales credited	11		8		34		15		7		6		16		8
Purchases billed	95		109		268		271		19		32		56		99

Net Intercompany Payables

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

	IPL		WPL
	September 30, 2018	December 31, 2017	September 30, 2018	December 31, 2017
Net payables to Corporate Services	$109	$114	$65	$61

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
	2018		2017		2018		2017
ATC billings to WPL		$26		$26		$79		$79
WPL billings to ATC	3		2		8		8