Segments Of Business (Tables)

12 Months Ended

Dec. 31, 2022

Segment Reporting Information [Line Items]

Schedule of Segments of Business

Certain financial information relating to Alliant Energy’s business segments, which represent the services provided to its customers, was as follows (in millions):

					ATC Holdings,
	Utility				Non-utility,	Alliant Energy
2022	Electric	Gas	Other	Total	Parent and Other	Consolidated
Revenues	$3,421	$642	$49	$4,112	$93	$4,205
Depreciation and amortization	601	56	7	664	7	671
Operating income	805	97	3	905	23	928
Interest expense				269	56	325
Equity income from unconsolidated investments, net	(1)	—	—	(1)	(50)	(51)
Income taxes				16	6	22
Net income attributable to Alliant Energy common shareowners				675	11	686
Total assets	16,571	1,631	860	19,062	1,101	20,163
Investments in equity method subsidiaries	20	—	—	20	522	542
Construction and acquisition expenditures	1,318	74	—	1,392	92	1,484

					ATC Holdings,
	Utility				Non-utility,	Alliant Energy
2021	Electric	Gas	Other	Total	Parent and Other	Consolidated
Revenues	$3,081	$456	$49	$3,586	$83	$3,669
Depreciation and amortization	591	54	6	651	6	657
Operating income (loss)	716	63	(11)	768	27	795
Interest expense				244	33	277
Equity income from unconsolidated investments, net	(2)	—	—	(2)	(60)	(62)
Income tax expense (benefit)				(87)	13	(74)
Net income attributable to Alliant Energy common shareowners				618	41	659
Total assets	14,924	1,487	1,103	17,514	1,039	18,553
Investments in equity method subsidiaries	17	—	—	17	491	508
Construction and acquisition expenditures	980	90	—	1,070	99	1,169

					ATC Holdings,
	Utility				Non-utility,	Alliant Energy
2020	Electric	Gas	Other	Total	Parent and Other	Consolidated
Revenues	$2,920	$373	$49	$3,342	$74	$3,416
Depreciation and amortization	556	49	5	610	5	615
Operating income (loss)	643	74	(1)	716	24	740
Interest expense				243	32	275
Equity income from unconsolidated investments, net	(2)	—	—	(2)	(59)	(61)
Income tax expense (benefit)				(66)	9	(57)
Net income attributable to Alliant Energy common shareowners				573	41	614
Total assets	14,358	1,413	990	16,761	949	17,710
Investments in equity method subsidiaries	11	—	—	11	465	476
Construction and acquisition expenditures	1,109	182	2	1,293	73	1,366

IPL [Member]

Segment Reporting Information [Line Items]

Schedule of Segments of Business

Certain financial information relating to IPL’s business segments, which represent the services provided to its customers, was as follows (in millions):

2022	Electric	Gas	Other	Total
Revenues	$1,859	$351	$46	$2,256
Depreciation and amortization	342	32	7	381
Operating income	397	53	3	453
Interest expense				148
Income tax benefit				(50)
Net income available for common stock				360
Total assets	8,686	872	517	10,075
Construction and acquisition expenditures	336	36	—	372

2021	Electric	Gas	Other	Total
Revenues	$1,752	$265	$46	$2,063
Depreciation and amortization	338	31	6	375
Operating income (loss)	420	43	(3)	460
Interest expense				139
Income tax benefit				(36)
Net income available for common stock				350
Total assets	8,602	819	575	9,996
Construction and acquisition expenditures	342	42	—	384

2020	Electric	Gas	Other	Total
Revenues	$1,695	$208	$44	$1,947
Depreciation and amortization	321	30	5	356
Operating income	358	50	2	410
Interest expense				139
Income tax benefit				(47)
Net income available for common stock				324
Total assets	8,518	766	565	9,849
Construction and acquisition expenditures	626	59	2	687

WPL [Member]

Segment Reporting Information [Line Items]

Schedule of Segments of Business

Certain financial information relating to WPL’s business segments, which represent the services provided to its customers, was as follows (in millions):

2022	Electric	Gas	Other	Total
Revenues	$1,562	$291	$3	$1,856
Depreciation and amortization	259	24	—	283
Operating income	408	44	—	452
Interest expense				121
Income taxes				66
Net income				315
Total assets	7,885	759	343	8,987
Construction and acquisition expenditures	982	38	—	1,020

2021	Electric	Gas	Other	Total
Revenues	$1,329	$191	$3	$1,523
Depreciation and amortization	253	23	—	276
Operating income (loss)	296	20	(8)	308
Interest expense				105
Income tax benefit				(51)
Net income				268
Total assets	6,322	668	528	7,518
Construction and acquisition expenditures	638	48	—	686

2020	Electric	Gas	Other	Total
Revenues	$1,225	$165	$5	$1,395
Depreciation and amortization	235	19	—	254
Operating income (loss)	285	24	(3)	306
Interest expense				104
Income tax benefit				(19)
Net income				249
Total assets	5,840	647	425	6,912
Construction and acquisition expenditures	483	123	—	606