SEGMENT INFORMATION: Level 4 (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Segment Reporting Information
Electric utility revenues	$ 338,699	$ 331,768	$ 648,160	$ 633,732
Total operating revenues	339,952	333,006	650,058	635,550
Net Income Attributable to IDACORP, Inc.	62,593	50,096	98,704	83,101
Net Income Attributable to IDACORP, Inc.	62,288	49,831	98,430	82,933
Total assets	6,206,117		6,206,117		$ 6,045,405
Idaho Power Company
Segment Reporting Information
Electric utility revenues				633,732
Net Income Attributable to IDACORP, Inc.	60,637	48,381	96,493	80,863
Total assets	$ 6,133,502		6,133,502
IERCo's ownership percentage in Bridger Coal Company	33.00%
All Other
Segment Reporting Information
Total operating revenues	$ 1,253	1,238	1,898	1,818
Net Income Attributable to IDACORP, Inc.	1,651	1,450	1,937	2,070
Total assets	153,529		153,529
Eliminations
Segment Reporting Information
Total operating revenues	0	0	0	0
Net Income Attributable to IDACORP, Inc.	0	$ 0	0	$ 0
Total assets	$ (80,914)		$ (80,914)