Receivables (Gross Write-offs For Accounts Receivable) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Gross write-offs for accounts receivable, originated in 2022	$ 3	$ 11
Gross write-offs for accounts receivable, originated in 2023	6	8
IPL [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Gross write-offs for accounts receivable, originated in 2022	2	7
Gross write-offs for accounts receivable, originated in 2023	4	5
WPL [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Gross write-offs for accounts receivable, originated in 2022	1	4
Gross write-offs for accounts receivable, originated in 2023	$ 2	$ 3