INCOME TAXES: Level 4 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Income Tax Expense [Line Items]
Income tax at statutory rates (federal and state)	$ 17,456		$ 13,006
Additional ADITC amortization	0		(825)
Other	(6,345)	[1]	(3,848)	[1]
Income tax (benefit) expense	11,111		8,333
Effective tax rate	24.90%		25.10%
Idaho Power Company
Income Tax Expense [Line Items]
Income tax at statutory rates (federal and state)	18,543		14,128
Additional ADITC amortization	0		(825)
Other	(5,165)	[1]	(2,988)	[1]
Income tax (benefit) expense	$ 13,378		$ 10,315
Effective tax rate	28.20%		28.50%

[1] "Other" is primarily comprised of Idaho Power's regulatory flow-through tax adjustments, which are listed in the rate reconciliation table in Note 2 to the consolidated financial statements included in IDACORP's and Idaho Power's Annual Report on Form 10-K for the year ended December 31, 2012.