Jointly Owned Electric Facilities (Tables)

12 Months Ended

Dec. 31, 2024

Jointly Owned Utility Plant, Net Ownership Amount [Abstract]

Schedule of Utility Plant in Service for Colstrip And Accumulated Depreciation

The Company’s share of utility plant in service for Colstrip and accumulated depreciation (inclusive of the ARO assets and accumulated amortization) were as follows as of December 31 (dollars in millions):

	2024			2023
Utility plant in service	$	401		$	394
Accumulated depreciation		(355	)		(334	)