Receivables (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Receivables [Line Items]
Gross write-offs for accounts receivable, originated in 2022	$ 5
IPL [Member]
Receivables [Line Items]
Gross write-offs for accounts receivable, originated in 2022	3
WPL [Member]
Receivables [Line Items]
Gross write-offs for accounts receivable, originated in 2022	2
Receivables Sold [Member] | IPL [Member]
Receivables [Line Items]
Available capacity	21
Receivables Sold [Member] | IPL [Member] | Financial Asset, Past Due [Member]
Receivables [Line Items]
Outstanding receivables past due	$ 26