Balance Sheet Components (Tables)

6 Months Ended

Jun. 30, 2025

Balance Sheet Related Disclosures [Abstract]

Schedule of Inventory

Inventories of materials and supplies, emission allowances, fuel stock and stored natural gas are recorded at average cost and consisted of the following as of June 30, 2025 and December 31, 2024 (dollars in millions):

	June 30,		December 31,
	2025		2024
Materials and supplies	$	101	$	99
Emission allowances		102		79
Stored natural gas		7		10
Fuel stock		6		5
Total	$	216	$	193

Schedule of Other Current Assets

Other current assets consisted of the following as of June 30, 2025 and December 31, 2024 (dollars in millions):

	June 30,		December 31,
	2025		2024
Prepayments	$	55	$	37
Income taxes receivable		35		32
Insurance proceeds receivable		22		—
Derivative assets net of collateral		3		11
Collateral posted for derivative instruments after netting with outstanding    derivatives		12		—
Notes receivable		9		—
Other		14		11
Total	$	150	$	91

Schedule of Net Utility Property Recorded at Original Cost Net of Accumulated Depreciation

Net utility property, which is recorded at original cost, net of accumulated depreciation, consisted of the following as of June 30, 2025 and December 31, 2024 (dollars in millions):

	June 30,		December 31,
	2025		2024
Utility plant in service	$	8,365	$	8,180
Construction work in progress		274		238
Total		8,639		8,418
Less: Accumulated depreciation and amortization		2,506		2,431
Total	$	6,133	$	5,987

Other Property and Investments-Net and Other Non-Current Assets

Other property and investments-net and other non-current assets consisted of the following as of June 30, 2025 and December 31, 2024 (dollars in millions):

	June 30,		December 31,
	2025		2024
Equity investments	$	146	$	157
Operating lease ROU assets		65		66
Finance lease ROU assets		31		33
Non-utility property		14		33
Notes receivable		10		16
Long-term prepaid license fees		14		18
Pension asset		39		35
Investment in affiliated trust		12		12
Deferred compensation assets		9		9
Other		22		20
Total	$	362	$	399

Other Current Liabilities

Other current liabilities consisted of the following as of June 30, 2025 and December 31, 2024 (dollars in millions):

	June 30, 2025		December 31, 2024
Accrued taxes other than income taxes	$	26	$	34
Derivative liabilities net of collateral		22		14
Employee paid time off accruals		36		32
Accrued interest		24		24
Pensions and other postretirement benefits		15		15
Other		56		65
Total	$	179	$	184

Schedule of Other Non-Current Liabilities and Deferred Credits

Other non-current liabilities and deferred credits consisted of the following as of June 30, 2025 and December 31, 2024 (dollars in millions):

	June 30, 2025		December 31, 2024
Operating lease liabilities	$	63	$	62
Finance lease liabilities		34		35
Deferred investment tax credits		28		28
Climate Commitment Act obligations		106		77
Asset retirement obligations		16		18
Derivative liabilities net of collateral		11		12
Other		21		21
Total	$	279	$	253

Schedule of Regulatory Assets and Liabilities

Regulatory assets and liabilities consisted of the following as of June 30, 2025 and December 31, 2024 (dollars in millions):

	June 30, 2025				December 31, 2024
	Current		Non-Current		Current		Non-Current
Regulatory Assets
Energy commodity derivatives	$	30	$	14	$	27	$	14
Deferred Climate Commitment Act costs		19		—		50		—
Deferred power costs		17		29		9		27
Decoupling surcharge		17		13		12		12
Income tax related assets		—		246		—		246
Pension and other postretirement benefit plans		—		104		—		106
Interest rate swaps		—		169		—		172
AFUDC above FERC allowed rate		—		49		—		49
Settlement with Coeur d'Alene Tribe		—		35		—		36
Advanced meter infrastructure		—		25		—		26
Utility plant abandoned		3		38		4		38
COVID-19 deferrals		—		9		—		12
Demand side management programs		—		44		—		38
Other regulatory assets		36		76		35		71
Total regulatory assets	$	122	$	851	$	137	$	847
Regulatory Liabilities
Other income tax related liabilities	$	6	$	56	$	5	$	59
Excess deferred income taxes		14		273		14		279
Deferred Climate Commitment Act revenues		31		—		44		—
Deferred power costs		9		3		8		6
Deferred natural gas costs		34		—		25		—
Decoupling rebate		—		6		4		—
Utility plant retirement costs		—		464		—		448
Interest rate swaps		—		23		—		24
COVID-19 deferrals		—		7		—		10
Other regulatory liabilities		14		11		8		8
Total regulatory liabilities	$	108	$	843	$	108	$	834