Redeemable Stock of Subsidiaries (Narrative) (Details) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2019 USD ($) series quarter $ / shares	Dec. 31, 2018 USD ($) series quarter $ / shares	Dec. 31, 2017 USD ($)
Temporary Equity [Line Items]
Temporary Equity, Accretion to Redemption Value		$ 6	$ 4
Temporary equity carrying amount		888	879	$ 837
Temporary Equity, Other Changes		10	34
Temporary Equity, Net Income		(7)	2
Colon [Domain]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount	[1]	210	201
Temporary Equity, Other Changes		10	34
IPALCO Enterprises, Inc. [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount		618	618
IPL Subsidiary
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount		60	60
Temporary equity carrying amount		$ 60	$ 60
Number of preferred stock series | series		5	5
Temporary equity annual dividend requirement		$ 3	$ 3
Number of consecutive quarters without paid dividends to invoke board of directors election rule | quarter		4	4
IPL Subsidiary | Minimum
Temporary Equity [Line Items]
Temporary equity, redemption price per share | $ / shares		$ 100	$ 100
IPL Subsidiary | Maximum
Temporary Equity [Line Items]
Temporary equity, redemption price per share | $ / shares		$ 118	$ 118
Other Comprehensive Income (Loss) [Member]
Temporary Equity [Line Items]
Temporary Equity, Other Changes		$ 0	$ 2

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