Regulatory Matters (Tables)

9 Months Ended

Sep. 30, 2022

Regulatory Assets [Line Items]

Regulatory Assets

Regulatory assets were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021
Tax-related	$913	$934	$842	$884	$71	$50
Pension and OPEB costs	436	462	216	228	220	234
Asset retirement obligations	145	128	104	89	41	39
Commodity cost recovery	129	42	2	2	127	40
Derivatives	102	8	67	4	35	4
Assets retired early	75	92	56	66	19	26
IPL’s DAEC PPA amendment	72	90	72	90	—	—
WPL’s Western Wisconsin gas distribution expansion investments	49	52	—	—	49	52
Other	120	132	64	80	56	52
	$2,041	$1,940	$1,423	$1,443	$618	$497

Regulatory Liabilities

Regulatory liabilities were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021
Tax-related	$582	$585	$304	$312	$278	$273
Cost of removal obligations	398	384	258	252	140	132
Derivatives	312	166	164	77	148	89
WPL’s West Riverside liquidated damages	33	36	—	—	33	36
Electric transmission cost recovery	16	51	4	27	12	24
Other	46	49	31	23	15	26
	$1,387	$1,271	$761	$691	$626	$580

IPL [Member]

Regulatory Assets [Line Items]

Regulatory Assets

Regulatory assets were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021
Tax-related	$913	$934	$842	$884	$71	$50
Pension and OPEB costs	436	462	216	228	220	234
Asset retirement obligations	145	128	104	89	41	39
Commodity cost recovery	129	42	2	2	127	40
Derivatives	102	8	67	4	35	4
Assets retired early	75	92	56	66	19	26
IPL’s DAEC PPA amendment	72	90	72	90	—	—
WPL’s Western Wisconsin gas distribution expansion investments	49	52	—	—	49	52
Other	120	132	64	80	56	52
	$2,041	$1,940	$1,423	$1,443	$618	$497

Regulatory Liabilities

Regulatory liabilities were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021
Tax-related	$582	$585	$304	$312	$278	$273
Cost of removal obligations	398	384	258	252	140	132
Derivatives	312	166	164	77	148	89
WPL’s West Riverside liquidated damages	33	36	—	—	33	36
Electric transmission cost recovery	16	51	4	27	12	24
Other	46	49	31	23	15	26
	$1,387	$1,271	$761	$691	$626	$580

WPL [Member]

Regulatory Assets [Line Items]

Regulatory Assets

Regulatory assets were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021
Tax-related	$913	$934	$842	$884	$71	$50
Pension and OPEB costs	436	462	216	228	220	234
Asset retirement obligations	145	128	104	89	41	39
Commodity cost recovery	129	42	2	2	127	40
Derivatives	102	8	67	4	35	4
Assets retired early	75	92	56	66	19	26
IPL’s DAEC PPA amendment	72	90	72	90	—	—
WPL’s Western Wisconsin gas distribution expansion investments	49	52	—	—	49	52
Other	120	132	64	80	56	52
	$2,041	$1,940	$1,423	$1,443	$618	$497

Regulatory Liabilities

Regulatory liabilities were comprised of the following items (in millions):

	Alliant Energy		IPL		WPL
	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021	September 30, 2022	December 31, 2021
Tax-related	$582	$585	$304	$312	$278	$273
Cost of removal obligations	398	384	258	252	140	132
Derivatives	312	166	164	77	148	89
WPL’s West Riverside liquidated damages	33	36	—	—	33	36
Electric transmission cost recovery	16	51	4	27	12	24
Other	46	49	31	23	15	26
	$1,387	$1,271	$761	$691	$626	$580