INCOME TAXES: Level 4 (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Expense [Line Items]
Income tax at statutory rates (federal and state)				$ 27,590	$ 27,909
First mortgage bond redemption				0	1,261
Excess deferred income tax reversal				3,262	3,880
Other	[1]			(12,984)	(12,770)
Income Tax Expense		$ 7,028	$ 7,105	$ 11,344	$ 9,998
Effective tax rate				10.60%	9.20%
Idaho Power Company
Income Tax Expense [Line Items]
Income tax at statutory rates (federal and state)				$ 26,975	$ 27,539
First mortgage bond redemption				0	1,261
Excess deferred income tax reversal				3,262	3,880
Other	[1]			(11,676)	(11,902)
Income Tax Expense		$ 7,371	$ 7,345	$ 12,037	$ 10,496
Effective tax rate				11.50%	9.80%

[1] "Other" is primarily comprised of the net tax effect of Idaho Power's regulatory flow-through tax adjustments.