Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2023

Schedule Of Regulatory Assets and Liabilities [Line Items]

Schedule of Regulatory Assets

Regulatory assets represent costs that are expected to be recovered in future regulated rates. The Company's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining Life	2023		2022
Deferred net power costs	2 years	$	1,769	$	1,478
Asset retirement obligations	17 years	930		835
Deferred income taxes(1)	Various	435		373
Employee benefit plans(2)	14 years	414		490
Demand side management	10 years	245		224
Unrealized losses on regulated derivative contracts	1 year	173		112
Levelized depreciation	28 years	167		151
Cost of removal	26 years	143		—
Environmental costs	30 years	139		111
Asset disposition costs	Various	135		231
Wildfire mitigation and vegetation management costs	Various	114		111
Other	Various	901		946
Total regulatory assets		$	5,565	$	5,062
Reflected as:
Current assets		$	1,398	$	1,319
Noncurrent assets		4,167		3,743
Total regulatory assets		$	5,565	$	5,062

(1)Amounts primarily represent income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

(2)Includes amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized.

Schedule of Regulatory Liabilities

The Company's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining Life	2023		2022
Cost of removal(1)	26 years	$	2,741	$	2,578
Deferred income taxes(2)	Various	2,733		2,901
Asset retirement obligations	30 years	364		250
Revenue sharing mechanisms	Various	243		426
Levelized depreciation	27 years	230		245
Employee benefit plans(3)	Various	211		180
Unrealized gains on regulated derivative contracts	1 year	7		343
Other	Various	289		446
Total regulatory liabilities		$	6,818	$	7,369
Reflected as:
Current liabilities		$	174	$	299
Noncurrent liabilities		6,644		7,070
Total regulatory liabilities		$	6,818	$	7,369

(1)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

(2)Amounts primarily represent income tax liabilities related to the 2017 federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

(3)Includes amounts not yet recognized as a component of net periodic benefit cost that are expected to be returned to customers in future periods when recognized.

PAC

Schedule Of Regulatory Assets and Liabilities [Line Items]

Schedule of Regulatory Assets

Regulatory assets represent costs that are expected to be recovered in future rates. PacifiCorp's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining
	Life	2023		2022
Employee benefit plans(1)	16 years	$	279	$	290
Utah mine disposition(2)	Various	79		115
Deferred net power costs	2 years	1,117		546
Unrealized loss on derivative contracts	1 year	76		—
Environmental costs	30 years	139		111
Asset retirement obligation	28 years	300		275
Demand side management (DSM)	10 years	245		224
Wildfire mitigation and vegetation management costs	Various	114		111
Other	Various	224		208
Total regulatory assets		$	2,573	$	1,880
Reflected as:
Current assets		$	631	$	275
Noncurrent assets		1,942		1,605
Total regulatory assets		$	2,573	$	1,880

(1)Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in rates when recognized.

(2)Amounts represent regulatory assets established as a result of the Utah mine disposition in 2015 for the United Mine Workers of America ("UMWA") 1974 Pension Plan withdrawal and closure costs incurred to date considered probable of recovery. Refer to Note 10 for additional information.

Schedule of Regulatory Liabilities

Regulatory liabilities represent income to be recognized or amounts to be returned to customers in future periods. PacifiCorp's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining
	Life	2023		2022
Cost of removal(1)	26 years	$	1,456	$	1,332
Deferred income taxes(2)	Various	1,006		1,164
Unrealized gain on regulated derivatives	N/A	—		270
Other	Various	148		173
Total regulatory liabilities		$	2,610	$	2,939
Reflected as:
Current liabilities		$	70	$	96
Noncurrent liabilities		2,540		2,843
Total regulatory liabilities		$	2,610	$	2,939

(1)Amounts represent estimated costs, as generally accrued through depreciation rates, of removing property, plant and equipment in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

(2)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable of being passed on to customers, partially offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

MEC

Schedule Of Regulatory Assets and Liabilities [Line Items]

Schedule of Regulatory Assets

Regulatory assets represent costs that are expected to be recovered in future regulated rates. MidAmerican Energy's regulatory assets reflected on the Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining Life	2023		2022
Asset retirement obligations(1)	12 years	$	541	$	469
Employee benefit plans(2)	9 years	16		47
Unrealized loss on regulated derivative contracts	1 year	11		—
Other	Various	32		34
Total		$	600	$	550

(1)Amount predominantly relates to AROs for fossil-fueled and wind-powered generating facilities. Refer to Note 11 for a discussion of AROs.

(2)Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized.

Schedule of Regulatory Liabilities

Regulatory liabilities represent amounts expected to be returned to customers in future periods. MidAmerican Energy's regulatory liabilities reflected on the Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining Life	2023		2022
Cost of removal(1)	28 years	$	411	$	392
Asset retirement obligations(2)	30 years	360		247
Iowa electric revenue sharing(3)	Various	127		312
Deferred income taxes(4)	Various	102		72
Pre-funded AFUDC on transmission MVPs(5)	56 years	32		34
Employee benefit plans(6)	N/A	16		—
Unrealized gain on regulated derivative contracts	1 year	—		31
Other	Various	31		31
Total		$	1,079	$	1,119

(1)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing utility plant in accordance with accepted regulatory practices. Amounts are deducted from rate base or otherwise accrue a carrying cost.

(2)Amount represents the excess of nuclear decommission trust assets over the related ARO. Refer to Note 11 for a discussion of AROs.

(3)Represents accruals associated with a regulatory arrangement in Iowa in which equity returns exceeding specified thresholds reduce utility plant and retail electric energy cost recoveries as required.

(4)Amounts primarily represent income tax liabilities primarily related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to state accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

(5)Represents AFUDC accrued on transmission MVPs that is deducted from rate base as a result of the inclusion of related construction work-in-progress in rate base.

(6)Represents amounts not yet recognized as a component of net periodic benefit cost that are to be returned to customers in future periods when recognized.

NPC

Schedule Of Regulatory Assets and Liabilities [Line Items]

Schedule of Regulatory Assets

Regulatory assets represent costs that are expected to be recovered in future rates. Nevada Power's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining Life	2023		2022
Deferred energy costs	1 year	$	575	$	654
Merger costs from 1999 merger	21 years	100		105
Asset retirement obligations	7 years	69		69
Unrealized loss on regulated derivative contracts	1 year	68		75
Decommissioning costs	3 years	56		116
Deferred operating costs	18 years	41		67
Other	Various	176		208
Total regulatory assets		$	1,085	$	1,294
Reflected as:
Current assets		$	586	$	666
Noncurrent assets		499		628
Total regulatory assets		$	1,085	$	1,294

Schedule of Regulatory Liabilities

Regulatory liabilities represent amounts that are expected to be returned to customers in future periods. Nevada Power's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining Life	2023		2022
Deferred income taxes(1)	Various	$	525	$	560
Cost of removal(2)	30 years	368		358
Earning sharing mechanism	3 years	115		114
Other	Various	52		106
Total regulatory liabilities		$	1,060	$	1,138
Reflected as:
Current liabilities		$	43	$	45
Noncurrent liabilities		1,017		1,093
Total regulatory liabilities		$	1,060	$	1,138

(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

(2)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices.

SPPC

Schedule Of Regulatory Assets and Liabilities [Line Items]

Schedule of Regulatory Assets

Regulatory assets represent costs that are expected to be recovered in future rates. Sierra Pacific's regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining Life	2023		2022
Natural disaster protection plan	1 year	$	78	$	69
Deferred energy costs	1 year	77		277
Merger costs from 1999 merger	23 years	60		63
Employee benefit plans (1)	8 years	48		57
Deferred operating costs	4 years	25		35
Other	Various	93		110
Total regulatory assets		$	381	$	611
Reflected as:
Current assets		$	161	$	357
Noncurrent assets		220		254
Total regulatory assets		$	381	$	611

(1)Represents amounts not yet recognized as a component of net periodic benefit cost that are expected to be included in regulated rates when recognized.

Schedule of Regulatory Liabilities

Regulatory liabilities represent amounts that are expected to be returned to customers in future periods. Sierra Pacific's regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted
	Average
	Remaining Life	2023		2022
Deferred income taxes(1)	Various	$	206	$	223
Cost of removal(2)	31 years	211		200
Other	Various	22		32
Total regulatory liabilities		$	439	$	455
Reflected as:
Current liabilities		$	15	$	19
Noncurrent liabilities		424		436
Total regulatory liabilities		$	439	$	455

(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to accelerated tax depreciation and certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

(2)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices.

EEGH

Schedule Of Regulatory Assets and Liabilities [Line Items]

Schedule of Regulatory Assets

Eastern Energy Gas' regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted Average Remaining Life	2023		2022
Employee benefit plans(1)	11 years	$	33	$	32
Other	Various	21		16
Total regulatory assets		$	54	$	48
Reflected as:
Other current assets		$	9	$	8
Other assets		45		40
Total regulatory assets		$	54	$	48

(1)Represents costs expected to be recovered through future rates generally over the expected remaining service period of plan participants by certain rate-regulated subsidiaries.

Schedule of Regulatory Liabilities

Eastern Energy Gas' regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted Average Remaining Life	2023		2022
Income taxes refundable through future rates(1)	Various	$	425	$	406
Other postretirement benefit costs(2)	Various	124		123
Provision for rate refunds(3)		—		90
Cost of removal(4)	47 years	85		82
Other	Various	22		21
Total regulatory liabilities		$	656	$	722
Reflected as:
Current liabilities		$	33	$	126
Noncurrent liabilities		623		596
Total regulatory liabilities		$	656	$	722

(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

(2)Reflects a regulatory liability for the collection of postretirement benefit costs allowed in rates in excess of expense incurred.

(3)Reflects amounts refunded to customers in late February 2023 in connection with the EGTS rate case. See below for more information.

(4)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Refer to Note 11 for more information.

EGTS

Schedule Of Regulatory Assets and Liabilities [Line Items]

Schedule of Regulatory Assets

Regulatory assets represent costs that are expected to be recovered in future regulated rates. EGTS' regulatory assets reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted Average Remaining Life	2023		2022
Employee benefit plans(1)	11 years	$	32	$	31
Other	Various	4		8
Total regulatory assets		$	36	$	39
Reflected as:
Other current assets		$	3	$	5
Other assets		33		34
Total regulatory assets		$	36	$	39

(1)Represents costs expected to be recovered through future rates generally over the expected remaining service period of plan participants.

Schedule of Regulatory Liabilities

Regulatory liabilities represent income to be recognized or amounts expected to be returned to customers in future periods. EGTS' regulatory liabilities reflected on the Consolidated Balance Sheets consist of the following as of December 31 (in millions):

	Weighted Average Remaining Life	2023		2022
Income taxes refundable through future rates(1)	Various	$	377	$	382
Other postretirement benefit costs(2)	Various	124		123
Provision for rate refunds(3)		—		90
Cost of removal(4)	47 years	28		24
Other	Various	16		8
Total regulatory liabilities		$	545	$	627
Reflected as:
Current liabilities		$	22	$	109
Noncurrent liabilities		523		518
Total regulatory liabilities		$	545	$	627

(1)Amounts primarily represent income tax liabilities related to the federal tax rate change from 35% to 21% that are probable to be passed on to customers, offset by income tax benefits related to certain property-related basis differences and other various differences that were previously passed on to customers and will be included in regulated rates when the temporary differences reverse.

(2)Reflects a regulatory liability for the collection of postretirement benefit costs allowed in rates in excess of expense incurred.

(3)Reflects amounts refunded to customers in late February 2023 in connection with the EGTS rate case. See below for more information.

(4)Amounts represent estimated costs, as accrued through depreciation rates and exclusive of ARO liabilities, of removing regulated property, plant and equipment in accordance with accepted regulatory practices. Refer to Note 11 for more information.