FAIR VALUE MEASUREMENTS: Fair Value Measurements Level 4 (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, All Levels Transfers, Amount	$ 0	$ 0
Asset derivatives	404,000	634,000
Money market funds	1,000,000
Trading securities: Equity securities	102,000	141,000
Available-for-sale securities: Equity securities	24,459,000	44,942,000
Liability derivatives	4,972,000	3,961,000
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	340,000	506,000
Money market funds	1,000,000
Trading securities: Equity securities	102,000	141,000
Available-for-sale securities: Equity securities	24,459,000	44,942,000
Liability derivatives	286,000	17,000
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	64,000	128,000
Money market funds	0
Trading securities: Equity securities	0	0
Available-for-sale securities: Equity securities	0	0
Liability derivatives	4,686,000	3,944,000
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset derivatives	0	0
Money market funds	0
Trading securities: Equity securities	0	0
Available-for-sale securities: Equity securities	0	0
Liability derivatives	0	0
Idaho Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	10,000,000	100,000
Available-for-sale securities: Equity securities	24,459,000	$ 44,942,000
Idaho Power Company | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$ 10,000,000