Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income (loss) for common stock	$ (104,402)	$ 41,118	$ (1,357,764)	$ 150,449
Net unrealized gains (losses) on available-for-sale investment securities:
Net unrealized gains (losses) on available-for-sale investment securities arising during the period, net of taxes of $13,470, $(13,918), $7,878 and $(11,860), respectively	36,795	(38,016)	21,520	(32,395)
Amortization of unrealized holding losses on held-to-maturity securities, net of taxes of $1,231, $1,354, $3,565 and $4,050, respectively	3,366	3,699	9,740	11,065
Derivatives qualifying as cash flow hedges:
Unrealized interest rate hedging losses arising during the period, net of taxes of $(291), $(185), $(24) and $(237), respectively	(838)	(535)	(69)	(684)
Reclassification adjustment to net income, net of taxes of $(18), $(17), $(52) and $(50), respectively	(52)	(47)	(151)	(143)
Retirement benefit plans:
Adjustment for amortization of prior service credit and net gains recognized during the period in net periodic benefit cost, net of taxes of $(431), $(153), $(740) and $(397), respectively	(1,244)	(446)	(2,138)	(1,160)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes of $462, $163, $781 and $458, respectively	1,333	470	2,251	1,321
Other comprehensive income (loss), net of taxes	39,360	(34,875)	31,153	(21,996)
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	$ (65,042)	$ 6,243	$ (1,326,611)	$ 128,453