Electric utility segment - Condensed Consolidating Statement of Changes in Common Stock Equity (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Increase (decrease) in stockholders' equity
Beginning balance	$ 2,249,377	$ 2,237,955	$ 2,202,499	$ 2,233,504	$ 2,303,642	$ 2,390,884	$ 2,202,499	$ 2,390,884
Net income for common stock	41,118	54,610	54,721	62,082	52,541	69,167	150,449	183,790
Other comprehensive loss, net of taxes	(34,875)	(7,609)	20,488	(96,012)	(87,840)	(117,159)	(21,996)	(301,011)
Common stock dividends	(39,455)	(39,447)	(39,446)	(38,315)	(38,301)	(38,301)
Ending balance	2,224,354	2,249,377	2,237,955	2,162,922	2,233,504	2,303,642	2,224,354	2,162,922
Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance	2,371,889	2,358,884	2,344,170	2,289,595	2,276,884	2,261,899	2,344,170	2,261,899
Net income for common stock	43,461	45,299	47,009	49,764	44,135	46,409	135,769	140,308
Other comprehensive loss, net of taxes	(77)	(44)	(45)	108	51	51	(166)	210
Common stock dividends	(32,250)	(32,250)	(32,250)	(31,475)	(31,475)	(31,475)	(96,750)	(94,425)
Ending balance	2,383,023	$ 2,371,889	2,358,884	2,307,992	$ 2,289,595	2,276,884	2,383,023	2,307,992
Consolidating adjustments | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance			(701,833)			(676,237)	(701,833)	(676,237)
Net income for common stock	(3,005)			(10,577)			(25,960)	(36,475)
Other comprehensive loss, net of taxes	9			(1)			32	(4)
Common stock dividends							24,450	23,700
Ending balance	(703,311)			(689,016)			(703,311)	(689,016)
Hawaiian Electric | Reportable Legal Entities | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance			2,344,170			2,261,899	2,344,170	2,261,899
Net income for common stock	43,461			49,764			135,769	140,308
Other comprehensive loss, net of taxes	(77)			108			(166)	210
Common stock dividends							(96,750)	(94,425)
Ending balance	2,383,023			2,307,992			2,383,023	2,307,992
Hawaii Electric Light | Reportable Legal Entities | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance			344,720			332,900	344,720	332,900
Net income for common stock	7,419			4,959			20,884	17,994
Other comprehensive loss, net of taxes	(1)			2			(9)	4
Common stock dividends							(13,425)	(12,300)
Ending balance	352,170			338,598			352,170	338,598
Maui Electric | Reportable Legal Entities | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance			357,036			343,260	357,036	343,260
Net income for common stock	(4,414)			5,618			5,076	18,481
Other comprehensive loss, net of taxes	(8)			(1)			(23)	0
Common stock dividends							(11,025)	(11,400)
Ending balance	351,064			350,341			351,064	350,341
Other subsidiary | Reportable Legal Entities | Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance			$ 77			$ 77	77	77
Net income for common stock	0			0			0	0
Other comprehensive loss, net of taxes	0			0			0	0
Ending balance	$ 77			$ 77			$ 77	$ 77