Redeemable Stocks of Subsidiaries (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Carrying Amount		$ 867		$ 888
Colon [Domain]
Temporary Equity [Line Items]
Temporary Equity, Other Charges		0	$ 10
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount	[1]	189		210
IPALCO Enterprises, Inc. [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount		618		618
IPL Subsidiary [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount		$ 60		$ 60

[1] Characteristics of quotas are similar to common stock.