Preferred Stock (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Temporary Equity [Line Items]
Redemption of IPL's cumulative preferred stock	$ 0	$ 0	$ 200
IPL [Member]
Temporary Equity [Line Items]
Redemption of IPL's cumulative preferred stock	$ 0	$ 0	200
IPL [Member] | Cumulative Preferred Stock [Member]
Temporary Equity [Line Items]
Shares outstanding (in shares)				8,000
Cumulative preferred stock rate				5.10%
Preferred stock redemption price per share (in dollars per share)				$ 25
Redemption of IPL's cumulative preferred stock			200
Non-cash charge, preferred stock redemption			$ 5