Electric utility segment - Condensed consolidating statement of changes in common stock equity (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Increase (decrease) in stockholders' equity
Beginning balance	$ 2,233,504	$ 2,303,642	$ 2,390,884	$ 2,367,329	$ 2,321,293	$ 2,337,502	$ 2,390,884	$ 2,337,502
Net income for common stock	62,082	52,541	69,167	63,415	63,872	64,358	183,790	191,645
Other comprehensive income, net of taxes	(96,012)	(87,840)	(117,159)	(11,305)	16,472	(44,016)	(301,011)	(38,849)
Common stock dividends	(38,315)	(38,301)	(38,301)	(37,166)	(37,155)	(37,156)
Ending balance	2,162,922	2,233,504	2,303,642	2,383,543	2,367,329	2,321,293	2,162,922	2,383,543
Hawaiian Electric Consolidated
Increase (decrease) in stockholders' equity
Beginning balance	2,289,595	2,276,884	2,261,899	2,171,396	2,157,385	2,141,918	2,261,899	2,141,918
Net income for common stock	49,764	44,135	46,409	50,342	41,901	43,358	140,308	135,601
Other comprehensive income, net of taxes	108	51	51	106	35	34	210	175
Common stock dividends	(31,475)	(31,475)	(31,475)	(27,925)	(27,925)	(27,925)	(94,425)	(83,775)
Ending balance	2,307,992	$ 2,289,595	2,276,884	2,193,919	$ 2,171,396	2,157,385	2,307,992	2,193,919
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaiian Electric
Increase (decrease) in stockholders' equity
Beginning balance			2,261,899			2,141,918	2,261,899	2,141,918
Net income for common stock	49,764			50,342			140,308	135,601
Other comprehensive income, net of taxes	108			106			210	175
Common stock dividends							(94,425)	(83,775)
Ending balance	2,307,992			2,193,919			2,307,992	2,193,919
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaii Electric Light
Increase (decrease) in stockholders' equity
Beginning balance			332,900			317,451	332,900	317,451
Net income for common stock	4,959			4,888			17,994	17,187
Other comprehensive income, net of taxes	2			2			4	3
Common stock dividends							(12,300)	(10,950)
Ending balance	338,598			323,691			338,598	323,691
Hawaiian Electric Consolidated | Reportable Legal Entities | Maui Electric
Increase (decrease) in stockholders' equity
Beginning balance			343,260			309,363	343,260	309,363
Net income for common stock	5,618			7,140			18,481	18,095
Other comprehensive income, net of taxes	(1)			0			0	0
Common stock dividends							(11,400)	(11,326)
Ending balance	350,341			316,132			350,341	316,132
Hawaiian Electric Consolidated | Reportable Legal Entities | Other subsidiaries
Increase (decrease) in stockholders' equity
Beginning balance			77			77	77	77
Net income for common stock	0			0			0	0
Other comprehensive income, net of taxes	0			0			0	0
Ending balance	77			77			77	77
Hawaiian Electric Consolidated | Consolidating adjustments
Increase (decrease) in stockholders' equity
Beginning balance			$ (676,237)			$ (626,891)	(676,237)	(626,891)
Net income for common stock	(10,577)			(12,028)			(36,475)	(35,282)
Other comprehensive income, net of taxes	(1)			(2)			(4)	(3)
Common stock dividends							23,700	22,276
Ending balance	$ (689,016)			$ (639,900)			$ (689,016)	$ (639,900)