Disaggregation of Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 4,027	$ 4,205	$ 3,669
IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,110	2,256	2,063
WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,827	1,856	1,523
Electric [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,345	3,421	3,081
Electric [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,761	1,859	1,752
Electric [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,584	1,562	1,329
Electric [Member] | Retail - Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,220	1,233	1,115
Electric [Member] | Retail - Residential [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	641	673	620
Electric [Member] | Retail - Residential [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	579	560	495
Electric [Member] | Retail - Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	820	821	763
Electric [Member] | Retail - Commercial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	519	536	508
Electric [Member] | Retail - Commercial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	301	285	255
Electric [Member] | Retail - Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	968	965	893
Electric [Member] | Retail - Industrial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	501	538	505
Electric [Member] | Retail - Industrial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	467	427	388
Electric [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenues	213	233	187
Electric [Member] | Wholesale [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	62	64	57
Electric [Member] | Wholesale [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	151	169	130
Electric [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	124	169	123
Electric [Member] | Other [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	38	48	62
Electric [Member] | Other [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	86	121	61
Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues	540	642	456
Gas [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	300	351	265
Gas [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	240	291	191
Gas [Member] | Retail - Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	316	371	257
Gas [Member] | Retail - Residential [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	176	202	146
Gas [Member] | Retail - Residential [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	140	169	111
Gas [Member] | Retail - Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	163	197	139
Gas [Member] | Retail - Commercial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	86	101	79
Gas [Member] | Retail - Commercial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	77	96	60
Gas [Member] | Retail - Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	16	20	17
Gas [Member] | Retail - Industrial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	11	14	12
Gas [Member] | Retail - Industrial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	5	6	5
Gas [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	45	54	43
Gas [Member] | Other [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	27	34	28
Gas [Member] | Other [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	18	20	15
Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues	52	49	49
Other Utility [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	49	46	46
Other Utility [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	3	3	3
Other Utility [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	7	10	13
Other Utility [Member] | Other [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	4	7	10
Other Utility [Member] | Other [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	3	3	3
Other Utility [Member] | Steam [Member]
Disaggregation of Revenue [Line Items]
Revenues	45	39	36
Other Utility [Member] | Steam [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	45	39	36
Non-Utility and Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	90	93	83
Non-Utility and Other [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 90	$ 93	$ 83