Disaggregation of Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 4,205	$ 3,669	$ 3,416
IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,256	2,063	1,947
WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,856	1,523	1,395
Electric [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,421	3,081	2,920
Electric [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,859	1,752	1,695
Electric [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,562	1,329	1,225
Electric [Member] | Retail - Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,233	1,115	1,093
Electric [Member] | Retail - Residential [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	673	620	602
Electric [Member] | Retail - Residential [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	560	495	491
Electric [Member] | Retail - Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	821	763	718
Electric [Member] | Retail - Commercial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	536	508	474
Electric [Member] | Retail - Commercial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	285	255	244
Electric [Member] | Retail - Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	965	893	841
Electric [Member] | Retail - Industrial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	538	505	488
Electric [Member] | Retail - Industrial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	427	388	353
Electric [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenues	233	187	168
Electric [Member] | Wholesale [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	64	57	57
Electric [Member] | Wholesale [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	169	130	111
Electric [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	169	123	100
Electric [Member] | Other [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	48	62	74
Electric [Member] | Other [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	121	61	26
Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues	642	456	373
Gas [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	351	265	208
Gas [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	291	191	165
Gas [Member] | Retail - Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues	371	257	214
Gas [Member] | Retail - Residential [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	202	146	116
Gas [Member] | Retail - Residential [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	169	111	98
Gas [Member] | Retail - Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues	197	139	107
Gas [Member] | Retail - Commercial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	101	79	59
Gas [Member] | Retail - Commercial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	96	60	48
Gas [Member] | Retail - Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues	20	17	12
Gas [Member] | Retail - Industrial [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	14	12	8
Gas [Member] | Retail - Industrial [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	6	5	4
Gas [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	54	43	40
Gas [Member] | Other [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	34	28	25
Gas [Member] | Other [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	20	15	15
Other Utility [Member]
Disaggregation of Revenue [Line Items]
Revenues	49	49	49
Other Utility [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	46	46	44
Other Utility [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	3	3	5
Other Utility [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	10	13	13
Other Utility [Member] | Other [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	7	10	8
Other Utility [Member] | Other [Member] | WPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	3	3	5
Other Utility [Member] | Steam [Member]
Disaggregation of Revenue [Line Items]
Revenues	39	36	36
Other Utility [Member] | Steam [Member] | IPL [Member]
Disaggregation of Revenue [Line Items]
Revenues	39	36	36
Non-Utility and Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	93	83	74
Non-Utility and Other [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 93	$ 83	$ 74