Redeemable Stocks of Subsidiaries (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Carrying Amount		$ 886		$ 879
Colon [Domain]
Temporary Equity [Line Items]
Temporary Equity, Other Charges		10	$ 34
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount	[1]	208		201
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] ⁽¹⁾  Characteristics of quotas are similar to common stock.