Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 344	$ 39
Accounts receivable, less allowance for expected credit losses	509	440
Production fuel, at weighted average cost	49	51
Gas stored underground, at weighted average cost	124	82
Materials and supplies, at weighted average cost	126	113
Regulatory assets	177	104
Other	364	240
Total current assets	1,693	1,069
Property, plant and equipment, net	15,858	14,987
Investments:
ATC Holdings	351	338
Other	200	179
Total investments	551	517
Other assets:
Regulatory assets	1,864	1,836
Deferred charges and other	239	144
Total other assets	2,103	1,980
Total assets	20,205	18,553
Current liabilities:
Current maturities of long-term debt	658	633
Commercial paper	383	515
Accounts payable	786	436
Accrued taxes	86	58
Regulatory liabilities	229	186
Other	280	226
Total current liabilities	2,422	2,054
Long-term debt, net (excluding current portion)	7,570	6,735
Other liabilities:
Deferred tax liabilities	1,919	1,927
Regulatory liabilities	1,158	1,085
Pension and other benefit obligations	349	374
Other	522	388
Total other liabilities	3,948	3,774
Commitments and contingencies (Note 13)
Common equity:
Common stock	3	3
Additional paid-in capital	2,767	2,749
Retained earnings	3,508	3,250
Shares in deferred compensation trust - 395,224 and 383,532 shares at a weighted average cost of $32.23 and $30.59 per share	(13)	(12)
Total common equity	6,265	5,990
Total liabilities and equity	20,205	18,553
IPL [Member]
Current assets:
Cash and cash equivalents	45	34
Accounts receivable, less allowance for expected credit losses	286	241
Income tax refunds receivable	1	8
Production fuel, at weighted average cost	31	29
Gas stored underground, at weighted average cost	66	40
Materials and supplies, at weighted average cost	77	70
Regulatory assets	108	73
Other	134	69
Total current assets	748	564
Property, plant and equipment, net	8,013	7,983
Other assets:
Regulatory assets	1,315	1,370
Deferred charges and other	132	79
Total other assets	1,447	1,449
Total assets	10,208	9,996
Current liabilities:
Accounts payable	232	173
Accounts payable to associated companies	37	39
Accrued taxes	69	56
Accrued interest	35	36
Regulatory liabilities	105	84
Other	112	67
Total current liabilities	590	455
Long-term debt, net (excluding current portion)	3,645	3,643
Other liabilities:
Deferred tax liabilities	1,029	1,083
Regulatory liabilities	656	607
Pension and other benefit obligations	118	127
Other	314	312
Total other liabilities	2,117	2,129
Commitments and contingencies (Note 13)
Common equity:
Common stock	33	33
Additional paid-in capital	2,807	2,807
Retained earnings	1,016	929
Total common equity	3,856	3,769
Total liabilities and equity	10,208	9,996
WPL [Member]
Current assets:
Cash and cash equivalents	299	2
Accounts receivable, less allowance for expected credit losses	211	188
Production fuel, at weighted average cost	18	23
Gas stored underground, at weighted average cost	58	42
Materials and supplies, at weighted average cost	47	41
Regulatory assets	69	31
Prepaid gross receipts tax	31	40
Other	130	86
Total current assets	863	453
Property, plant and equipment, net	7,371	6,538
Other assets:
Regulatory assets	549	466
Deferred charges and other	115	61
Total other assets	664	527
Total assets	8,898	7,518
Current liabilities:
Current maturities of long-term debt	250	250
Commercial paper	0	236
Accounts payable	470	190
Accounts payable to associated companies	51	39
Regulatory liabilities	124	102
Other	93	73
Total current liabilities	988	890
Long-term debt, net (excluding current portion)	2,769	2,179
Other liabilities:
Deferred tax liabilities	783	753
Regulatory liabilities	502	478
Pension and other benefit obligations	148	159
Other	352	236
Total other liabilities	1,785	1,626
Commitments and contingencies (Note 13)
Common equity:
Common stock	66	66
Additional paid-in capital	2,123	1,704
Retained earnings	1,167	1,053
Total common equity	3,356	2,823
Total liabilities and equity	$ 8,898	$ 7,518