FAIR VALUE MEASUREMENTS: Level 4 (Details) - USD ($)		Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	[1]	$ 69,177,000	$ 56,048,000
Derivative Assets		15,016,000	1,995,000
Equity Securities, FV-NI		47,752,000	50,733,000
Derivative Liabilities		104,000	144,000
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount		0	0
Idaho Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds		11,616,000	40,038,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	[1]	69,177,000	56,048,000
Derivative Assets		15,016,000	1,995,000
Equity Securities, FV-NI		47,752,000	50,733,000
Derivative Liabilities		0	134,000
Fair Value, Inputs, Level 1 [Member] | Idaho Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds		11,616,000	40,038,000
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	0
Equity Securities, FV-NI		0	0
Derivative Liabilities		104,000	10,000
Fair Value, Inputs, Level 2 [Member] | Idaho Power Company
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
Derivative Liabilities		0	0
Fair Value, Inputs, Level 3 [Member] | Idaho Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds		$ 0	$ 0

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