FAIR VALUE MEASUREMENTS: Level 4 (Details) - USD ($) $ in Thousands		Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	[1]	$ 77,838	$ 80,406
Derivative Assets		19,696	6,598
Equity Securities, FV-NI		22,698	54,431
Derivative Liabilities		5,598	5,747
Idaho Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds		21,900	10,393
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	[1]	77,838	80,406
Derivative Assets		19,696	6,596
Equity Securities, FV-NI		22,698	54,431
Assets, Fair Value Disclosure		0	0
Derivative Liabilities		0	34
Fair Value, Inputs, Level 1 [Member] | Idaho Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds		21,900	10,393
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	[1]	0	0
Derivative Assets		0	2
Equity Securities, FV-NI		0	0
Assets, Fair Value Disclosure		0	0
Derivative Liabilities		5,598	5,713
Fair Value, Inputs, Level 2 [Member] | Idaho Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds		0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	[1]	0	0
Derivative Assets		0	0
Equity Securities, FV-NI		0	0
Assets, Fair Value Disclosure		0	0
Derivative Liabilities		0	0
Fair Value, Inputs, Level 3 [Member] | Idaho Power Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds		0	0
Fair Value Measured at Net Asset Value Per Share
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		$ 1,864	$ 1,363

[1] Holding company only. Does not include amounts held by Idaho Power.