CHANGES IN IDAHO POWER RETAINED EARNINGS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Changes in Idaho Power Retained Earnings
Balance at beginning of period	$ 1,542,175	$ 1,432,584	$ 1,531,543	$ 1,426,528
Net Income	53,400	62,593	96,037	98,704
Dividends to parent			(64,077)	(59,941)
Common stock dividends	(31,932)	(29,863)	(63,986)	(59,949)
Balance at end of period	1,563,399	1,465,009	1,563,399	1,465,009
Idaho Power Company
Changes in Idaho Power Retained Earnings
Balance at beginning of period	1,418,775	1,314,472	1,409,245	1,308,702
Net Income	51,176	60,637	92,760	96,493
Dividends to parent	(31,932)	(29,863)	(63,986)	(59,949)
Balance at end of period	$ 1,438,019	$ 1,345,246	$ 1,438,019	$ 1,345,246