Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2022		Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 19		$ 39
Accounts receivable, less allowance for expected credit losses	490		440
Production fuel, at weighted average cost	55		51
Gas stored underground, at weighted average cost	64		82
Materials and supplies, at weighted average cost	121		113
Regulatory assets	188		104
Other	371		240
Total current assets	1,308	[1]	1,069
Property, plant and equipment, net	15,453	[1]	14,987
Investments:
ATC Holdings	351		338
Other	195		179
Total investments	546		517
Other assets:
Regulatory assets	1,863		1,836
Deferred charges and other	221		144
Total other assets	2,084		1,980
Total assets	19,391		18,553
Current liabilities:
Current maturities of long-term debt	733		633
Commercial paper	399		515
Accounts payable	584		436
Accrued taxes	58		58
Regulatory liabilities	218		186
Other	284		226
Total current liabilities	2,276		2,054
Long-term debt, net (excluding current portion)	6,981		6,735
Other liabilities:
Deferred tax liabilities	1,971		1,927
Regulatory liabilities	1,145		1,085
Pension and other benefit obligations	356		374
Other	496		388
Total other liabilities	3,968	[1]	3,774
Commitments and contingencies (Note 13)
Common equity:
Common stock	3		3
Additional paid-in capital	2,759		2,749
Retained earnings	3,387		3,250
Shares in deferred compensation trust - 388,363 and 383,532 shares at a weighted average cost of $31.72 and $30.59 per share	(12)		(12)
Total common equity	6,137		5,990
Noncontrolling interest	29		0
Total equity	6,166		5,990
Total liabilities and equity	19,391		18,553
Consolidated Variable Interest Entity [Member]
Current assets:
Total current assets	1
Property, plant and equipment, net	428
Other liabilities:
Total other liabilities	8
IPL [Member]
Current assets:
Cash and cash equivalents	13		34
Accounts receivable, less allowance for expected credit losses	269		241
Income tax refunds receivable	8		8
Production fuel, at weighted average cost	37		29
Gas stored underground, at weighted average cost	27		40
Materials and supplies, at weighted average cost	73		70
Regulatory assets	111		73
Other	149		69
Total current assets	687		564
Property, plant and equipment, net	7,997		7,983
Other assets:
Regulatory assets	1,379		1,370
Deferred charges and other	121		79
Total other assets	1,500		1,449
Total assets	10,184		9,996
Current liabilities:
Accounts payable	225		173
Accounts payable to associated companies	37		39
Accrued taxes	51		56
Accrued interest	35		36
Regulatory liabilities	100		84
Other	115		67
Total current liabilities	563		455
Long-term debt, net (excluding current portion)	3,645		3,643
Other liabilities:
Deferred tax liabilities	1,106		1,083
Regulatory liabilities	651		607
Pension and other benefit obligations	121		127
Other	316		312
Total other liabilities	2,194		2,129
Commitments and contingencies (Note 13)
Common equity:
Common stock	33		33
Additional paid-in capital	2,807		2,807
Retained earnings	942		929
Total common equity	3,782		3,769
Total equity	3,782		3,769
Total liabilities and equity	10,184		9,996
WPL [Member]
Current assets:
Cash and cash equivalents	4		2
Accounts receivable, less allowance for expected credit losses	208		188
Production fuel, at weighted average cost	18		23
Gas stored underground, at weighted average cost	37		42
Materials and supplies, at weighted average cost	46		41
Regulatory assets	77		31
Prepaid gross receipts tax	40		40
Other	113		86
Total current assets	543	[2]	453
Property, plant and equipment, net	6,985	[2]	6,538
Other assets:
Regulatory assets	484		466
Deferred charges and other	106		61
Total other assets	590		527
Total assets	8,118		7,518
Current liabilities:
Current maturities of long-term debt	250		250
Commercial paper	222		236
Accounts payable	300		190
Accounts payable to associated companies	20		39
Regulatory liabilities	118		102
Other	99		73
Total current liabilities	1,009		890
Long-term debt, net (excluding current portion)	2,180		2,179
Other liabilities:
Deferred tax liabilities	774		753
Regulatory liabilities	494		478
Pension and other benefit obligations	151		159
Other	327		236
Total other liabilities	1,746	[2]	1,626
Commitments and contingencies (Note 13)
Common equity:
Common stock	66		66
Additional paid-in capital	1,968		1,704
Retained earnings	1,120		1,053
Total common equity	3,154		2,823
Noncontrolling interest	29		0
Total equity	3,183		2,823
Total liabilities and equity	8,118		$ 7,518
WPL [Member] | Consolidated Variable Interest Entity [Member]
Current assets:
Total current assets	1
Property, plant and equipment, net	428
Other liabilities:
Total other liabilities	$ 8

[1] As of June 30, 2022, Alliant Energy’s assets of a consolidated VIE that may be used only to settle obligations of that VIE include $1 million of current assets and $428 million of property, plant and equipment, net, and Alliant Energy’s liabilities of that VIE that creditors do not have recourse to include $8 million of other liabilities. Refer to Note 1(b) for additional information.

[2] As of June 30, 2022, WPL’s assets of a consolidated VIE that may be used only to settle obligations of that VIE include $1 million of current assets and $428 million of property, plant and equipment, net, and WPL’s liabilities of that VIE that creditors do not have recourse to include $8 million of other liabilities. Refer to Note 1(b) for additional information.