Receivables (Gross Write-offs for Accounts Receivable (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
Gross write-offs for accounts receivable, originated in 2022	$ 12
Gross write-offs for accounts receivable, originated in 2023	13
IPL [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Gross write-offs for accounts receivable, originated in 2022	8
Gross write-offs for accounts receivable, originated in 2023	8
WPL [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Gross write-offs for accounts receivable, originated in 2022	4
Gross write-offs for accounts receivable, originated in 2023	$ 5