Balance Sheet Components (Tables)

9 Months Ended

Sep. 30, 2026

Balance Sheet Related Disclosures [Abstract]

Schedule of Inventory

Inventories of materials and supplies, emission allowances, stored natural gas, and fuel stock are recorded at average cost and consisted of the following as of September 30, 2026 and December 31, 2025 (dollars in millions):


		September 30,				December 31,
		2026				2025
Materials and supplies		$	89			$	87
Emission allowances			171				136
Stored natural gas			10				8
Fuel stock			6				5
Total		$	276			$	236

Schedule of Other Current Assets

Other current assets consisted of the following as of September 30, 2026 and December 31, 2025 (dollars in millions):


		September 30,				December 31,
		2026				2025
Prepayments		$	47			$	56
Income taxes receivable			10				39
Derivative assets net of collateral			4				8
Other			12				16
Total		$	73			$	119

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 September 30, 2026 and December 31, 2025 (dollars in millions):


		September 30,				December 31,
		2026				2025
Utility plant in service		$	8,669			$	8,591
Construction work in progress			426				303
Total			9,095				8,894
Less: Accumulated depreciation and amortization			2,427				2,575
Total		$	6,668			$	6,319

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 September 30, 2026 and December 31, 2025 (dollars in millions):


		September 30,				December 31,
		2026				2025
Equity investments		$	176			$	148
Operating lease ROU assets			63				64
Finance lease ROU assets			26				29
Non-utility property			10				12
Notes receivable			10				12
Long-term prepaid license fees			12				18
Pension asset			67				61
Investment in affiliated trust			12				12
Deferred compensation assets			9				9
Other			8				23
Total		$	393			$	388

Other Current Liabilities

Other current liabilities consisted of the following as of September 30, 2026 and December 31, 2025 (dollars in millions):


		September 30, 2026				December 31, 2025
Accrued taxes other than income taxes		$	30			$	33
Derivative liabilities			21				18
Employee paid time off accruals			40				34
Accrued interest			47				27
Pensions and other postretirement benefits			17				16
Customer deposits			21				19
Other			45				54
Total		$	221			$	201

Schedule of Other Non-Current Liabilities and Deferred Credits

Other non-current liabilities and deferred credits consisted of the following as of September 30, 2026 and December 31, 2025 (dollars in millions):


		September 30, 2026				December 31, 2025
Operating lease liabilities		$	62			$	60
Finance lease liabilities			29				32
Deferred investment tax credits			27				27
Climate Commitment Act obligations			164				131
Asset retirement obligations			17				16
Derivative liabilities			9				10
Other			34				29
Total		$	342			$	305

Schedule of Regulatory Assets and Liabilities

Regulatory assets and liabilities consisted of the following as of September 30, 2026 and December 31, 2025 (dollars in millions):


		September 30, 2026								December 31, 2025
		Current				Non-Current				Current				Non-Current
Regulatory Assets
Energy commodity derivatives		$	33			$	13			$	18			$	12
Deferred Climate Commitment Act costs			3				—				24				—
Deferred power costs			55				53				17				71
Decoupling surcharge			54				35				27				21
Unamortized debt repurchase costs			—				4				—				5
Income tax related assets			—				255				—				246
Pension and other postretirement benefit plans			1				71				1				72
Interest rate swaps			—				160				—				165
AFUDC above FERC allowed rate			—				53				—				51
Settlement with Coeur d'Alene Tribe			—				34				—				34
Advanced meter infrastructure			3				18				3				20
Utility plant abandoned			2				11				2				31
Demand side management programs			—				51				—				57
Colstrip			2				31				2				31
Wildfire resiliency			17				26				9				17
Insurance deferrals			8				6				8				8
Other regulatory assets			20				35				24				30
Total regulatory assets		$	198			$	856			$	135			$	871
Regulatory Liabilities
Other income tax related liabilities		$	6			$	47			$	7			$	51
Excess deferred income taxes			13				257				13				266
Deferred Climate Commitment Act revenues			7				—				34				—
Deferred power costs			1				5				7				—
Deferred natural gas costs			23				—				33				—
Decoupling rebate			5				1				1				3
Utility plant retirement costs			—				495				—				468
Interest rate swaps			—				22				—				23
Provision for rate refund			7				—				13				—
Other regulatory liabilities			18				11				18				7
Total regulatory liabilities		$	80			$	838			$	126			$	818