INCOME TAXES: Level 4 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Income Tax Expense [Line Items]
Income tax at statutory rates (federal and state)	$ 17,935	$ 6,744	$ 30,941	$ 20,284
Additional ADITC amortization	825	(2,895)	0	(6,750)
Examination settlement	0	(3,428)	0	(3,428)
Other	(8,191)	(4,073)	(12,039)	(8,871)
Income tax (benefit) expense	10,569	(3,652)	18,902	1,235
Effective tax rate	23.00%	(21.20%)	23.90%	2.40%
Idaho Power Company
Income Tax Expense [Line Items]
Income tax at statutory rates (federal and state)	18,513	7,150	32,642	21,633
Additional ADITC amortization	825	(2,895)	0	(6,750)
Examination settlement	0	(3,428)	0	(3,428)
Other	(6,699)	(3,241)	(9,688)	(6,676)
Income tax (benefit) expense	$ 12,639	$ (2,414)	$ 22,954	$ 4,779
Effective tax rate	26.70%	(13.20%)	27.50%	8.60%