Electric utility segment - Condensed Consolidating Statement of Changes in Common Stock Equity (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Increase (decrease) in stockholders' equity
Beginning balance	$ 2,377,380	$ 2,344,841	$ 2,237,955	$ 2,202,499	$ 2,344,841	$ 2,202,499
Net income (loss) for common stock	(1,295,484)	42,122	54,610	54,721	(1,253,362)	109,331
Other comprehensive loss, net of taxes	1,594	(9,801)	(7,609)	20,488	(8,207)	12,879
Common stock dividends			(39,447)	(39,446)
Ending balance	1,085,273	2,377,380	2,249,377	2,237,955	1,085,273	2,249,377
Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance	2,435,282	2,409,110	2,358,884	2,344,170	2,409,110	2,344,170
Net income (loss) for common stock	(1,229,394)	39,221	45,299	47,009	(1,190,173)	92,308
Other comprehensive loss, net of taxes	(46)	(49)	(44)	(45)	(95)	(89)
Common stock dividends	(13,000)	(13,000)	(32,250)	(32,250)	(26,000)	(64,500)
Ending balance	1,192,842	2,435,282	2,371,889	2,358,884	1,192,842	2,371,889
Consolidating adjustments | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance		(722,211)		(701,833)	(722,211)	(701,833)
Net income (loss) for common stock	246,099		(11,414)		240,075	(22,955)
Other comprehensive loss, net of taxes	11		11		24	23
Common stock dividends						16,300
Ending balance	(482,112)		(708,465)		(482,112)	(708,465)
Hawaiian Electric | Reportable Legal Entities | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance		2,409,110		2,344,170	2,409,110	2,344,170
Net income (loss) for common stock	(1,229,394)		45,299		(1,190,173)	92,308
Other comprehensive loss, net of taxes	(46)		(44)		(95)	(89)
Common stock dividends					(26,000)	(64,500)
Ending balance	1,192,842		2,371,889		1,192,842	2,371,889
Hawaii Electric Light | Reportable Legal Entities | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance		359,790		344,720	359,790	344,720
Net income (loss) for common stock	(120,295)		7,075		(115,905)	13,465
Other comprehensive loss, net of taxes	(4)		(2)		(7)	(8)
Common stock dividends						(8,950)
Ending balance	243,878		349,227		243,878	349,227
Maui Electric | Reportable Legal Entities | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance		362,344		357,036	362,344	357,036
Net income (loss) for common stock	(125,804)		4,339		(124,170)	9,490
Other comprehensive loss, net of taxes	(7)		(9)		(17)	(15)
Common stock dividends						(7,350)
Ending balance	238,157		359,161		238,157	359,161
Other subsidiaries | Reportable Legal Entities | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance		$ 77		$ 77	77	77
Net income (loss) for common stock	0		0		0	0
Other comprehensive loss, net of taxes	0		0		0	0
Ending balance	$ 77		$ 77		$ 77	$ 77