CONTINGENCIES: Level 4 (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Regulatory Assets		$ 1,653,050	$ 1,501,961
Regulatory Assets		1,653,050	1,501,961
Energy efficiency regulatory asset
Loss Contingencies [Line Items]
Regulatory Assets	[1]	0	3,767
Regulatory Assets	[1]	$ 0	$ 3,767

[1]     The energy efficiency asset and liability represent the separate Idaho and Oregon jurisdiction balances at December 31, 2022, and December 31, 2023, respectively. During 2023, the balances changed from an asset to a liability in the Idaho jurisdiction.