Consolidated Statements of Common Equity - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	IPL [Member]	WPL [Member]	Common Stock [Member]	Common Stock [Member] IPL [Member]	Common Stock [Member] WPL [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] IPL [Member]	Additional Paid-in Capital [Member] WPL [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Retained Earnings [Member] IPL [Member]	Retained Earnings [Member] WPL [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Shares in Deferred Compensation Trust [Member]	Cumulative Preferred Stock [Member]	Cumulative Preferred Stock [Member] IPL [Member]
Beginning balance at Dec. 31, 2018					$ 2	$ 33	$ 66	$ 2,046	$ 2,223	$ 1,309	$ 2,546		$ 775	$ 775	$ 2	$ (10)	$ 200	$ 200
Beginning balance at Dec. 31, 2018	$ 4,786		$ 3,231	$ 2,150
Increase (Decrease) in Shareowners' Equity [Roll Forward]
Net income attributable to common shareowners	557		284								557		284
Net income	567		294	233										233
Common stock dividends	(337)		(168)	(144)							(337)		(168)	(144)
Equity forward settlements and Shareowner Direct Plan issuances	390							390
Capital contributions from parent			125	125					125	125
Equity-based compensation plans and other	10							10
Payments to redeem cumulative preferred stock of IPL	0		0
Other comprehensive income (loss), net of tax	(1)														(1)
Ending balance at Dec. 31, 2019					2	33	66	2,446	2,348	1,434	2,766		891	864	1	(10)	200	200
Ending balance at Dec. 31, 2019	5,405		3,472	2,364
Increase (Decrease) in Shareowners' Equity [Roll Forward]
Adoption of new accounting standard, net of tax		$ (9)										$ (9)
Net income attributable to common shareowners	614		324								614		324
Net income	624		334	249										249
Common stock dividends	(377)		(236)	(160)							(377)		(236)	(160)
Equity forward settlements and Shareowner Direct Plan issuances	247							247
Capital contributions from parent			404	25					404	25
Equity-based compensation plans and other	10							11								(1)
Payments to redeem cumulative preferred stock of IPL	0		0
Other comprehensive income (loss), net of tax	(2)														(2)
Ending balance at Dec. 31, 2020	5,688		3,764	2,478	2	33	66	2,704	2,752	1,459	2,994		979	953	(1)	(11)	200	200
Ending balance at Dec. 31, 2020	5,888		3,964	2,478
Increase (Decrease) in Shareowners' Equity [Roll Forward]
Adoption of new accounting standard, net of tax	2,994		979	953
Net income attributable to common shareowners	659		350								659		350
Net income	674		365	268										268
Common stock dividends	(403)		(400)	(168)							(403)		(400)	(168)
Equity forward settlements and Shareowner Direct Plan issuances	28				1			27
Capital contributions from parent			50	245					50	245
Equity-based compensation plans and other	17		5					18	5							(1)
Payments to redeem cumulative preferred stock of IPL	(200)		(200)														(200)	(200)
Other comprehensive income (loss), net of tax	1														1
Ending balance at Dec. 31, 2021	5,990		3,769	2,823	$ 3	$ 33	$ 66	$ 2,749	$ 2,807	$ 1,704	$ 3,250		$ 929	$ 1,053	$ 0	$ (12)	$ 0	$ 0
Ending balance at Dec. 31, 2021	5,990		3,769	2,823
Increase (Decrease) in Shareowners' Equity [Roll Forward]
Adoption of new accounting standard, net of tax	$ 3,250		$ 929	$ 1,053