Electric utility segment - Condensed consolidating statement of comprehensive income (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
Condensed Statement of Income Captions [Line Items]
Net income for common stock	$ 62,082	$ 52,541	$ 69,167	$ 63,415	$ 63,872	$ 64,358	$ 183,790	$ 191,645
Retirement benefit plans:
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	5,606			2,853			10,229	14,871
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	(5,303)			(2,799)			(9,572)	(14,421)
Other comprehensive loss, net of taxes	(96,012)	(87,840)	(117,159)	(11,305)	16,472	(44,016)	(301,011)	(38,849)
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	(33,930)			52,110			(117,221)	152,796
Hawaiian Electric Consolidated
Condensed Statement of Income Captions [Line Items]
Net income for common stock	49,764	44,135	46,409	50,342	41,901	43,358	140,308	135,601
Retirement benefit plans:
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	5,411			2,905			9,782	14,596
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	(5,303)			(2,799)			(9,572)	(14,421)
Other comprehensive loss, net of taxes	108	$ 51	$ 51	106	$ 35	$ 34	210	175
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	49,872			50,448			140,518	135,776
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaiian Electric
Condensed Statement of Income Captions [Line Items]
Net income for common stock	49,764			50,342			140,308	135,601
Retirement benefit plans:
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	5,411			2,905			9,782	14,596
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	(5,303)			(2,799)			(9,572)	(14,421)
Other comprehensive loss, net of taxes	108			106			210	175
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	49,872			50,448			140,518	135,776
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaii Electric Light
Condensed Statement of Income Captions [Line Items]
Net income for common stock	4,959			4,888			17,994	17,187
Retirement benefit plans:
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	768			393			1,366	2,062
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	(766)			(391)			(1,362)	(2,059)
Other comprehensive loss, net of taxes	2			2			4	3
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	4,961			4,890			17,998	17,190
Hawaiian Electric Consolidated | Reportable Legal Entities | Maui Electric
Condensed Statement of Income Captions [Line Items]
Net income for common stock	5,618			7,140			18,481	18,095
Retirement benefit plans:
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	732			393			1,938	1,915
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	(733)			(393)			(1,938)	(1,915)
Other comprehensive loss, net of taxes	(1)			0			0	0
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	5,617			7,140			18,481	18,095
Hawaiian Electric Consolidated | Reportable Legal Entities | Other subsidiaries
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 losses recognized during the period in net periodic benefit cost, net of taxes	0			0				0
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	0			0				0
Other comprehensive 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	(10,577)			(12,028)			(36,475)	(35,282)
Retirement benefit plans:
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	(1,500)			(786)			(3,304)	(3,977)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	1,499			784			3,300	3,974
Other comprehensive loss, net of taxes	(1)			(2)			(4)	(3)
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	$ (10,578)			$ (12,030)			$ (36,479)	$ (35,285)