Electric utility segment - Condensed Consolidating Statement of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Condensed Statement of Income Captions [Line Items]
Net income for common stock	$ 54,610	$ 54,721	$ 52,541	$ 69,167	$ 109,331	$ 121,708
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	(357)		122		(714)	4,623
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	426		56		851	(4,269)
Other comprehensive income (loss), net of taxes	(7,609)	20,488	(87,840)	(117,159)	12,879	(204,999)
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	47,001		(35,299)		122,210	(83,291)
Hawaiian Electric Consolidated
Condensed Statement of Income Captions [Line Items]
Net income for common stock	45,299	47,009	44,135	46,409	92,308	90,544
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	(470)		(5)		(940)	4,371
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	426		56		851	(4,269)
Other comprehensive income (loss), net of taxes	(44)	$ (45)	51	$ 51	(89)	102
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	45,255		44,186		92,219	90,646
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaiian Electric
Condensed Statement of Income Captions [Line Items]
Net income for common stock	45,299		44,135		92,308	90,544
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	(470)		(5)		(940)	4,371
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	426		56		851	(4,269)
Other comprehensive income (loss), net of taxes	(44)		51		(89)	102
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	45,255		44,186		92,219	90,646
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaii Electric Light
Condensed Statement of Income Captions [Line Items]
Net income for common stock	7,075		5,658		13,465	13,035
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	(55)		(72)		(111)	598
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	53		74		103	(596)
Other comprehensive income (loss), net of taxes	(2)		2		(8)	2
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	7,073		5,660		13,457	13,037
Hawaiian Electric Consolidated | Reportable Legal Entities | Maui Electric
Condensed Statement of Income Captions [Line Items]
Net income for common stock	4,339		6,579		9,490	12,863
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	(66)		603		(129)	1,206
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	57		(602)		114	(1,205)
Other comprehensive income (loss), net of taxes	(9)		1		(15)	1
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	4,330		6,580		9,475	12,864
Hawaiian Electric Consolidated | Reportable Legal Entities | Other subsidiary
Condensed Statement of Income Captions [Line Items]
Net income for common stock	0		0		0	0
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	0		0		0	0
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	0		0		0	0
Other comprehensive income (loss), net of taxes	0		0		0	0
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	0		0		0	0
Hawaiian Electric Consolidated | Consolidating adjustments
Condensed Statement of Income Captions [Line Items]
Net income for common stock	(11,414)		(12,237)		(22,955)	(25,898)
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	121		(531)		240	(1,804)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	(110)		528		(217)	1,801
Other comprehensive income (loss), net of taxes	11		(3)		23	(3)
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	$ (11,403)		$ (12,240)		$ (22,932)	$ (25,901)