Electric utility segment - Consolidating Statement of Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Statement of Income Captions [Line Items]
Net income for common stock	$ 241,138	$ 246,166	$ 197,824
Retirement benefit plans:
Net gains (losses) arising during the period, net of (taxes) benefits	188,020	153,121	(60,529)
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	19,659	19,253	23,689
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits	(199,936)	(171,345)	39,860
Other comprehensive income (loss), net of taxes	(283,495)	(51,269)	18,775
Comprehensive income attributable to Hawaiian Electric Industries, Inc.	(42,357)	194,897	216,599
Hawaiian Electric (parent only)
Condensed Statement of Income Captions [Line Items]
Net income for common stock	241,138	246,166	197,824
Hawaiian Electric Company, Inc. and Subsidiaries
Condensed Statement of Income Captions [Line Items]
Net income for common stock	188,929	177,642	169,340
Retirement benefit plans:
Net gains (losses) arising during the period, net of (taxes) benefits	187,193	151,523	(63,050)
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	18,884	19,461	21,550
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits	(199,936)	(171,345)	39,860
Other comprehensive income (loss), net of taxes	6,141	(361)	(1,640)
Comprehensive income attributable to Hawaiian Electric Industries, Inc.	195,070	177,281	167,700
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Hawaiian Electric (parent only)
Condensed Statement of Income Captions [Line Items]
Net income for common stock	188,929	177,642	169,340
Retirement benefit plans:
Net gains (losses) arising during the period, net of (taxes) benefits	187,193	151,523	(63,050)
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	18,884	19,461	21,550
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits	(199,936)	(171,345)	39,860
Other comprehensive income (loss), net of taxes	6,141	(361)	(1,640)
Comprehensive income attributable to Hawaiian Electric Industries, Inc.	195,070	177,281	167,700
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Hawaii Electric Light
Condensed Statement of Income Captions [Line Items]
Net income for common stock	21,816	21,180	27,493
Retirement benefit plans:
Net gains (losses) arising during the period, net of (taxes) benefits	44,411	17,902	(9,424)
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	2,811	2,749	3,179
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits	(46,841)	(20,585)	6,025
Other comprehensive income (loss), net of taxes	381	66	(220)
Comprehensive income attributable to Hawaiian Electric Industries, Inc.	22,197	21,246	27,273
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Maui Electric
Condensed Statement of Income Captions [Line Items]
Net income for common stock	25,677	24,173	20,011
Retirement benefit plans:
Net gains (losses) arising during the period, net of (taxes) benefits	44,386	16,572	(10,897)
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	2,584	2,553	2,763
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits	(46,694)	(18,898)	8,000
Other comprehensive income (loss), net of taxes	276	227	(134)
Comprehensive income attributable to Hawaiian Electric Industries, Inc.	25,953	24,400	19,877
Hawaiian Electric Company, Inc. and Subsidiaries | Consolidating adjustments
Condensed Statement of Income Captions [Line Items]
Net income for common stock	(47,493)	(45,353)	(47,504)
Retirement benefit plans:
Net gains (losses) arising during the period, net of (taxes) benefits	(88,797)	(34,474)	20,321
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	(5,395)	(5,302)	(5,942)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of (taxes) benefits	93,535	39,483	(14,025)
Other comprehensive income (loss), net of taxes	(657)	(293)	354
Comprehensive income attributable to Hawaiian Electric Industries, Inc.	$ (48,150)	$ (45,646)	$ (47,150)