NOTES PAYABLE: Level 4 (Details) (USD $)	Jun. 30, 2012 credit_agreement_extensions	Dec. 31, 2011
Short-term borrowings:
Commercial paper outstanding	$ 64,700,000	$ 54,200,000
Weighted-average annual interest rate	0.50%	0.47%
Credit facility:
Number of Credit Agreement Extensions	2
Extension Period of Credit Agreements	1 year
IDACORP
Short-term borrowings:
Commercial paper outstanding	54,700,000	54,200,000
Weighted-average annual interest rate	0.50%	0.47%
Credit facility:
Credit facility	125,000,000
Swingline Loan, Maximum Principal Outstanding	15,000,000
Letter of Credit, Maximum Borrowing Capacity	50,000,000
Line of Credit Facility, Right to Increase Borrowing Capacity	150,000,000
Amount outstanding on credit facility	0
IDACORP | Federal Funds Rate
Credit facility:
Interest Rate Addition to Base Rate	0.50%
IDACORP | LIBOR Rate
Credit facility:
Interest Rate Addition to Base Rate	1.00%
Idaho Power Company
Short-term borrowings:
Commercial paper outstanding	10,000,000	0
Weighted-average annual interest rate	0.49%	0.00%
Credit facility:
Credit facility	300,000,000
Swingline Loan, Maximum Principal Outstanding	30,000,000
Line of Credit Facility, Right to Increase Borrowing Capacity	450,000,000
Amount outstanding on credit facility	0
Regulatory authority to incur short-term indebtedness	$ 450,000,000