Schedule I - Condensed Financial Information of Parent - Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities:
Net cash provided by operating activities	$ 366,625	$ 491,626	$ 435,161
Investing Activities:
Net cash provided by (used in) investing activities	(280,492)	(258,177)	(280,441)
Financing Activities:
Dividends on common stock	(129,677)	(121,421)	(113,127)
Net change in short-term borrowings	0	0	(21,800)
Other	(2,534)	(2,964)	(348)
Net cash used in financing activities	(136,371)	(42,606)	(139,551)
Net (decrease) increase in cash and cash equivalents	(50,238)	190,843	15,169
Cash and cash equivalents at beginning of the year	267,492	76,649	61,480
Cash and cash equivalents at end of the year	217,254	267,492	76,649
IDACORP
Operating Activities:
Net cash provided by operating activities	112,745	197,185	113,849
Investing Activities:
Net cash provided by (used in) investing activities	0	0	0
Financing Activities:
Dividends on common stock	(129,682)	(121,421)	(113,127)
Net change in short-term borrowings	0	0	0
Change in intercompany notes payable	37,588	(2,867)	17,097
Other	(4,410)	(3,614)	(3,321)
Net cash used in financing activities	(96,504)	(127,902)	(99,351)
Net (decrease) increase in cash and cash equivalents	16,241	69,283	14,498
Cash and cash equivalents at beginning of the year	98,900	29,617	15,119
Cash and cash equivalents at end of the year	$ 115,141	$ 98,900	$ 29,617