Disaggregation of Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 3,981	$ 4,027	$ 4,205
IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,046	2,110	2,256
WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,845	1,827	1,856
Electric [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,372	3,345	3,421
Electric [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,747	1,761	1,859
Electric [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,625	1,584	1,562
Electric [Member] | Retail - Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,236	1,220	1,233
Electric [Member] | Retail - Residential [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	640	641	673
Electric [Member] | Retail - Residential [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	596	579	560
Electric [Member] | Retail - Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	821	820	821
Electric [Member] | Retail - Commercial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	525	519	536
Electric [Member] | Retail - Commercial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	296	301	285
Electric [Member] | Retail - Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	952	968	965
Electric [Member] | Retail - Industrial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	497	501	538
Electric [Member] | Retail - Industrial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	455	467	427
Electric [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenues	200	213	233
Electric [Member] | Wholesale [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	61	62	64
Electric [Member] | Wholesale [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	139	151	169
Electric [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	163	124	169
Electric [Member] | Other [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	24	38	48
Electric [Member] | Other [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	139	86	121
Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues	465	540	642
Gas [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	250	300	351
Gas [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	215	240	291
Gas [Member] | Retail - Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	275	316	371
Gas [Member] | Retail - Residential [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	148	176	202
Gas [Member] | Retail - Residential [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	127	140	169
Gas [Member] | Retail - Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	133	163	197
Gas [Member] | Retail - Commercial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	68	86	101
Gas [Member] | Retail - Commercial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	65	77	96
Gas [Member] | Retail - Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	11	16	20
Gas [Member] | Retail - Industrial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	7	11	14
Gas [Member] | Retail - Industrial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	4	5	6
Gas [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	46	45	54
Gas [Member] | Other [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	27	27	34
Gas [Member] | Other [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	19	18	20
Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues	54	52	49
Other Utility [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	49	49	46
Other Utility [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	5	3	3
Other Utility [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	14	7	10
Other Utility [Member] | Other [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	9	4	7
Other Utility [Member] | Other [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	5	3	3
Other Utility [Member] | Steam [Member]
Disaggregation of Revenue [Line Items]
Revenues	40	45	39
Other Utility [Member] | Steam [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	40	45	39
Non-Utility and Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	90	90	93
Non-Utility and Other [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 90	$ 90	$ 93