Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 20	$ 39
Accounts receivable, less allowance for expected credit losses	516	440
Production fuel, at weighted average cost	53	51
Gas stored underground, at weighted average cost	132	82
Materials and supplies, at weighted average cost	140	113
Regulatory assets	166	104
Other	223	240
Total current assets	1,250	1,069
Property, plant and equipment, net	16,247	14,987
Investments:
ATC Holdings	358	338
Other	201	179
Total investments	559	517
Other assets:
Regulatory assets	1,880	1,836
Deferred charges and other	227	144
Total other assets	2,107	1,980
Total assets	20,163	18,553
Current liabilities:
Current maturities of long-term debt	408	633
Commercial paper	642	515
Accounts payable	756	436
Regulatory liabilities	206	186
Other	351	284
Total current liabilities	2,363	2,054
Long-term debt, net (excluding current portion)	7,668	6,735
Other liabilities:
Deferred tax liabilities	1,943	1,927
Regulatory liabilities	1,118	1,085
Pension and other benefit obligations	277	374
Other	518	388
Total other liabilities	3,856	3,774
Commitments and contingencies (Note 17)
Common equity:
Common stock	3	3
Additional paid-in capital	2,777	2,749
Retained earnings	3,509	3,250
Shares in deferred compensation trust - 402,134 and 383,532 shares at a weighted average cost of $32.63 and $30.59 per share	(13)	(12)
Total common equity	6,276	5,990
Total liabilities and equity	20,163	18,553
IPL [Member]
Current assets:
Cash and cash equivalents	15	34
Accounts receivable, less allowance for expected credit losses	259	241
Production fuel, at weighted average cost	23	29
Gas stored underground, at weighted average cost	60	40
Materials and supplies, at weighted average cost	83	70
Regulatory assets	85	73
Other	93	77
Total current assets	618	564
Property, plant and equipment, net	8,046	7,983
Other assets:
Regulatory assets	1,301	1,370
Deferred charges and other	110	79
Total other assets	1,411	1,449
Total assets	10,075	9,996
Current liabilities:
Current maturities of long-term debt	0	0
Commercial paper	0	0
Accounts payable	239	173
Accounts payable to associated companies	28	39
Accrued taxes	52	56
Accrued interest	35	36
Regulatory liabilities	114	84
Other	113	67
Total current liabilities	581	455
Long-term debt, net (excluding current portion)	3,646	3,643
Other liabilities:
Deferred tax liabilities	1,047	1,083
Regulatory liabilities	640	607
Pension and other benefit obligations	62	127
Other	291	312
Total other liabilities	2,040	2,129
Commitments and contingencies (Note 17)
Common equity:
Common stock	33	33
Additional paid-in capital	2,807	2,807
Retained earnings	968	929
Total common equity	3,808	3,769
Total liabilities and equity	10,075	9,996
WPL [Member]
Current assets:
Cash and cash equivalents	5	2
Accounts receivable, less allowance for expected credit losses	244	188
Production fuel, at weighted average cost	29	23
Gas stored underground, at weighted average cost	73	42
Materials and supplies, at weighted average cost	54	41
Regulatory assets	81	31
Prepaid gross receipts tax	42	40
Other	60	86
Total current assets	588	453
Property, plant and equipment, net	7,722	6,538
Other assets:
Regulatory assets	579	466
Deferred charges and other	98	61
Total other assets	677	527
Total assets	8,987	7,518
Current liabilities:
Current maturities of long-term debt	0	250
Commercial paper	290	236
Accounts payable	456	190
Regulatory liabilities	92	102
Other	111	112
Total current liabilities	949	890
Long-term debt, net (excluding current portion)	2,770	2,179
Other liabilities:
Deferred tax liabilities	789	753
Regulatory liabilities	478	478
Pension and other benefit obligations	140	159
Other	370	236
Total other liabilities	1,777	1,626
Commitments and contingencies (Note 17)
Common equity:
Common stock	66	66
Additional paid-in capital	2,233	1,704
Retained earnings	1,192	1,053
Total common equity	3,491	2,823
Total liabilities and equity	$ 8,987	$ 7,518